A104421 - OEIS

A104421

Numbers n such that n, prime(n), prime(n)+n, prime(n)-n and prime(n)*n all numbers without the digit 1.

74, 75, 80, 86, 87, 95, 96, 350, 352, 354, 355, 357, 360, 364, 376, 536, 557, 564, 583, 584, 590, 592, 593, 594, 596, 599, 600, 623, 635, 639, 656, 659, 660, 665, 667, 674, 677, 678, 699, 700, 703, 706, 707, 724, 728, 734, 744, 750, 759, 762, 765, 766, 770

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

The graph is of quasi-piecewise linear character.

Any other reasonable function(s) of p and m not having digit 1?

Subsequence of A084368: a(1) = 75 = A084368(36), a(100) = 2744 = A084368(898). - Zak Seidov, Dec 04 2013

LINKS

Zak Seidov, Table of n, a(n) for n = 1..3000

EXAMPLE

For n = 74, p = prime(74) = 373, p + n = 447, p - n = 299, p*n = 27602.

For n = 256709, p = prime(256709) = 3599737, p + n = 3856446, p - n = 3343028, p*n = 924084885533.

MATHEMATICA

id[x_]:=IntegerDigits[x]; pr[i_]:=Prime[i]; ra=Range[3000]; A104421=Select[ra, Position[Union[id[ # ], id[pr[ # ]], id[pr[ # ]+# ], id[pr[ # ]-# ], id[pr[ # ]*# ]], 1]=={}&]

CROSSREFS

Cf. A038603, A084368, A104419-A104428.

Sequence in context: A000319 A033394 A114969 * A352382 A136948 A137139

Adjacent sequences: A104418 A104419 A104420 * A104422 A104423 A104424

KEYWORD

nonn,base

AUTHOR

Zak Seidov, Mar 07 2005

STATUS

approved