The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A240859 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A240859

Cubes k^3 such that k^3 + (k+1)^3 is semiprime.
(history; published version)

#12 by Harvey P. Dale at Tue Dec 15 11:55:48 EST 2015

STATUS

editing

approved

#11 by Harvey P. Dale at Tue Dec 15 11:55:42 EST 2015

MATHEMATICA

Transpose[Select[Partition[Range[250]^3, 2, 1], PrimeOmega[Total[#]] == 2&]] [[1]] (* Harvey P. Dale, Dec 15 2015 *)

STATUS

approved

editing

#10 by Charles R Greathouse IV at Mon Aug 25 10:55:50 EDT 2014

STATUS

editing

approved

#9 by Charles R Greathouse IV at Mon Aug 25 10:55:47 EDT 2014

PROG

(PARI) forprime(p=3, 1e4, if(isprime((p^2+3)/4), print1((p^3 - 3*p^2 + 3*p - 1)/8", "))) \\ Charles R Greathouse IV, Aug 25 2014

KEYWORD

nonn,easy

STATUS

approved

editing

#8 by N. J. A. Sloane at Mon Apr 14 11:24:00 EDT 2014

STATUS

editing

approved

#7 by N. J. A. Sloane at Mon Apr 14 11:23:26 EDT 2014

NAME

Cubes k ^3 such that k^3 + (k+k1 1)^3 is semiprime where k1 is the next cube after k.

STATUS

proposed

editing

Discussion

Mon Apr 14

11:24

N. J. A. Sloane: Jon's suggestion for the title seems clearer, so I used it.

#6 by Jon E. Schoenfield at Sun Apr 13 16:43:45 EDT 2014

STATUS

editing

proposed

#5 by Jon E. Schoenfield at Sun Apr 13 16:40:46 EDT 2014

NAME

Cubes k such that k+k1 is semiprime where k1 is the next cube after k.

STATUS

proposed

editing

Discussion

Sun Apr 13

16:43

Jon E. Schoenfield: The Name may be fine as it is. Here are some alternative ideas, in case any of them look better:
     Cubes k^3 such that k^3 + (k+1)^3 is semiprime.
     Numbers k^3 such that k^3 + (k+1)^3 is semiprime.
     Smaller of two consecutive cubes whose sum is semiprime.
(But I don't have any problem with the existing one!)  :-)

#4 by K. D. Bajpai at Sun Apr 13 16:39:21 EDT 2014

STATUS

editing

proposed

#3 by K. D. Bajpai at Sun Apr 13 16:38:32 EDT 2014

LINKS

K. D. Bajpai, <a href="/A240859/b240859.txt">Table of n, a(n) for n = 1..3689</a>