A225321 Numbers b such that b^(2^n) + 3 is prime for n from 0 to 4.

2564954, 4505138, 6319754, 10004666, 13410068, 28358686, 31079126, 31331314, 37983154, 40470296, 43452004, 58717498, 66643660, 67991588, 77422568, 77995658, 79257766, 98229376, 101553298, 123965218, 125464136, 126241688, 130818598, 130838170, 131305474

Offset

1,1

Comments

Generalized Fermat numbers of the form b^(2^n) + k with k = 3 here.

Links

Table of n, a(n) for n=1..25.

Mathematica

Select[Prime@Range[3, 10^6]-3, PrimeQ[#^2 + 3] && PrimeQ[#^4 + 3] && PrimeQ[#^8 + 3] && PrimeQ[#^16 + 3] &] (* Giovanni Resta, May 05 2013 *)

Crossrefs

Cf. A070694

Sequence in context: A345087 A345088 A234664 * A259563 A151938 A186049

Adjacent sequences: A225318 A225319 A225320 * A225322 A225323 A225324

Keyword

nonn

Author

Robin Garcia, May 05 2013

Extensions

Missing terms a(2) and a(5) and a(12)-a(25) from Giovanni Resta, May 05 2013

Status

approved