A224856 Numbers n such that 90*n + 29 and 90*n + 31 are twin primes.

0, 6, 7, 11, 14, 28, 30, 33, 37, 39, 47, 53, 61, 65, 74, 75, 76, 77, 84, 88, 91, 110, 128, 139, 152, 158, 170, 179, 180, 194, 195, 201, 215, 216, 228, 229, 251, 271, 282, 305, 308, 312, 334, 336, 345, 362, 366, 368, 370, 373, 383, 384, 410, 411, 413, 427, 450

Offset

1,2

Links

Table of n, a(n) for n=1..57.

Formula

A201739 INTERSECT A201819.

Maple

a:= proc(n) option remember; local k; for k from 1+
       `if`(n=1, -1, a(n-1)) while not (isprime(29+(90*k))
        and isprime(31+(90*k))) do od; k
    end:
seq(a(n), n=1..100);  # Alois P. Heinz, Jul 23 2013

Mathematica

Select[Range[0, 499], PrimeQ[90# + 29] && PrimeQ[90# + 31] &] (* copied from: Alonso del Arte, Jul 22 2013 *)

Crossrefs

Cf. A201739, A201819.

Sequence in context: A190612 A270431 A315832 * A182156 A166496 A267413

Adjacent sequences: A224853 A224854 A224855 * A224857 A224858 A224859

Keyword

nonn,easy

Author

J. W. Helkenberg, Jul 22 2013

Status

approved