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A224856 Numbers n such that 90*n + 29 and 90*n + 31 are twin primes. 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified September 28 19:16 EDT 2021. Contains 347717 sequences. (Running on oeis4.)