A174244 Least of 4 consecutive integers such that their product +-5 are primes.

1, 11, 31, 61, 116, 131, 321, 336, 906, 1081, 1101, 1216, 1601, 1821, 2081, 2106, 2356, 2491, 3051, 3101, 3281, 3286, 3496, 3736, 4576, 4716, 4861, 4876, 4886, 4981, 5066, 5096, 5301, 5881, 6066, 6121, 6401, 6761, 6916, 7061, 7446, 7556, 8021, 8041, 8056

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Mar 13 2010

Keywords

• nonn

Comments

1*2*3*4=24+-5 -> primes,..

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A014574, A174242, A174243.

Programs

Mathematica

f1[n_]:=PrimeQ[n-5]&&PrimeQ[n+5];f2[n_]:=n*(n+1)*(n+2)*(n+3);lst={};Do[If[f1[f2[n]],AppendTo[lst,n]],{n,8!}];lst
Select[Partition[Range[8200],4,1],AllTrue[Times@@#+{5,-5},PrimeQ]&][[All, 1]] (* or *) Select[ Range[ 8200],AllTrue[6#+11#^2+6#^3+#^4+{5,-5},PrimeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 20 2021 *)