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Revision History for A253550 (Bold, blue-underlined text is an addition; faded, red-underlined text is a deletion.)

Showing entries 1-10 | older changes
Shift one instance of the largest prime one step towards larger primes: a(1) = 1, for n>1: a(n) = (n / prime(g)) * prime(g+1), where g = A061395(n), index of the greatest prime dividing n.
(history; published version)
#11 by N. J. A. Sloane at Thu Jan 15 11:39:29 EST 2015
STATUS

proposed

approved

#10 by Antti Karttunen at Mon Jan 12 21:51:41 EST 2015
STATUS

editing

proposed

#9 by Antti Karttunen at Mon Jan 12 19:45:28 EST 2015
Discussion
Mon Jan 12
21:32
Antti Karttunen: By taking the inverse of A122111v4 given at the first PinkBox-comment Sun Jan 04 16:52, we get yet another "entanglement-recurrence" for A122111 (as it is self-inverse): 
(definec (A122111v5 n)
   (cond ((= n 1) n)
         ((zero? (A241917 n)) (A003961 (A122111v5 (A052126 n))))
         (else (* 2 (A122111v5 (A252462 n))))
   )
)
#8 by Antti Karttunen at Mon Jan 12 17:13:15 EST 2015
#7 by Antti Karttunen at Sun Jan 04 17:03:48 EST 2015
CROSSREFS

Cf. A102750 (same terms, but with 2 instead of 1, sorted into ascending order).

STATUS

proposed

editing

Discussion
Sun Jan 04
17:09
Antti Karttunen: We can represent A122111 as a binary tree ("entanglement") permutation, weird!
17:20
Antti Karttunen: And I assume the same holds for A241909 (see the first PinkBox-comment in https://oeis.org/draft/A253563).
Now, the next big question: can we represent A243505(n) (=  A122111(A064216(n))) in the same way? Because then that would give us a key to represent both A064216 and its inverse A048673 in similar way, my goal from a few months ago.
17:25
Antti Karttunen: Similarly, A250245/A250246 can be represented so, see e.g. https://oeis.org/draft/A252753 - https://oeis.org/draft/A252756
17:31
Antti Karttunen: Of course the fundamental question is: Can ANY permutation of natural numbers represented as an "entanglement permutation" of two pairs of complementary sets of natural numbers, A/B & C/D ? (Note that some of A, B, C & D could be identical with each other).
17:42
Antti Karttunen: And this started last night when I reclined in my bed and suddenly realized the "double-Ω formula": A001222(n) + A001222(A122111(n)) = A001222(n) + A061395(n), from which follows that A122111 preserves A252464:
(same-intfuns1? A252464 (COMPOSE A252464 A122111) 1024) --> #t
so permutations like https://oeis.org/draft/A253563 can be represented as  a(n) = A122111(A005940(n+1)).
Mon Jan 12
00:54
OEIS Server: This sequence has not been edited or commented on for a week
yet is not proposed for review.  If it is ready for review, please
visit https://oeis.org/draft/A253550 and click the button that reads
"These changes are ready for review by an OEIS Editor."

Thanks.
  - The OEIS Server
#6 by Antti Karttunen at Sun Jan 04 00:50:25 EST 2015
STATUS

editing

proposed

Discussion
Sun Jan 04
16:52
Antti Karttunen: (same-intfuns1? A122111 (COMPOSE A253565 A243071) 256) --> #t
AND:
(define (A122111v4 n)
  (cond ((<= n 2) n)
        ((even? n) (A253550 (A122111v4 (/ n 2))))
        (else (A253560 (A122111v4 (A064989 n))))
  )
)

AND (same-intfuns1? A122111 A122111v4 512) --> #t
#5 by Antti Karttunen at Sun Jan 04 00:46:53 EST 2015
FORMULA

a(n) <= A253560(n).

#4 by Antti Karttunen at Sat Jan 03 22:54:11 EST 2015
LINKS

Antti Karttunen, <a href="/A253550/b253550.txt">Table of n, a(n) for n = 1..10000</a>

#3 by Antti Karttunen at Sat Jan 03 21:21:39 EST 2015
NAME

allocated Shift one instance of the largest prime one step towards larger primes: a(1) = 1, for Antti Karttunenn>1: a(n) = (n / prime(g)) * prime(g+1), where g = A061395(n), index of the greatest prime dividing n.

DATA

1, 3, 5, 6, 7, 10, 11, 12, 15, 14, 13, 20, 17, 22, 21, 24, 19, 30, 23, 28, 33, 26, 29, 40, 35, 34, 45, 44, 31, 42, 37, 48, 39, 38, 55, 60, 41, 46, 51, 56, 43, 66, 47, 52, 63, 58, 53, 80, 77, 70, 57, 68, 59, 90, 65, 88, 69, 62, 61, 84, 67, 74, 99, 96, 85, 78, 71, 76, 87, 110, 73, 120, 79, 82, 105, 92, 91, 102, 83, 112, 135, 86, 89

OFFSET

1,2

FORMULA

a(1) = 1; for n>1: a(n) = A065091(A061395(n)) * A052126(n).

Other identities. For all n >= 1:

A252462(a(n)) = n. [A252462 works as an inverse function for this injection.]

PROG

(Scheme) (define (A253550 n) (if (= 1 n) n (* (A065091 (A061395 n)) (A052126 n))))

CROSSREFS
KEYWORD

allocated

nonn

AUTHOR

Antti Karttunen, Jan 03 2015

STATUS

approved

editing

#2 by Antti Karttunen at Sat Jan 03 18:48:31 EST 2015
KEYWORD

allocating

allocated