A129215 Numbers m such that 9!*m -+ 1 are twin primes.

3, 11, 22, 38, 52, 69, 125, 140, 154, 167, 169, 185, 198, 200, 205, 239, 299, 308, 335, 368, 376, 390, 405, 421, 482, 509, 574, 597, 610, 663, 684, 700, 701, 720, 763, 792, 795, 798, 840, 843, 855, 898, 907, 921, 954, 957

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

9!*a(n) are terms in A014574.

Mathematica

s={}; Do[m=362880k; If[PrimeQ[m-1]&&PrimeQ[m+1], AppendTo[s, k]], {k, 1000}]; s
With[{c=9!}, Select[Range[1000], And@@PrimeQ[c*#+{1, -1}]&]] (* Harvey P. Dale, Aug 27 2013 *)

Prog

(Magma) [m:m in [1..1000]| IsPrime(Factorial(9)*m+1) and IsPrime(Factorial(9)*m-1)]; // Marius A. Burtea, Dec 29 2019

Crossrefs

Cf. A014574 (average of twin prime pairs), A127545 (multiples of 7 in A014574), A137877.

Numbers m such that (N!*m -+ 1) are twin primes: A129213 (N=7), A129214 (N=8), A129216 (N=10).

Sequence in context: A184053 A240371 A158653 * A139593 A121471 A293766

Adjacent sequences: A129212 A129213 A129214 * A129216 A129217 A129218

Keyword

nonn

Author

Zak Seidov, Apr 03 2007

Status

approved