

A325439


Indices of primes of the form k^2 + 1 ending in 7.


2



3, 4, 6, 7, 9, 10, 11, 13, 14, 15, 16, 17, 19, 21, 23, 24, 26, 27, 29, 32, 34, 35, 36, 38, 40, 43, 45, 48, 50, 51, 52, 55, 56, 57, 59, 62, 64, 65, 66, 68, 70, 71, 72, 73, 75, 76, 77, 78, 79, 80, 81, 82, 83, 85, 87, 89, 90, 91, 95, 97, 98, 99, 101, 103, 107
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OFFSET

1,1


COMMENTS

This sequence is presumably infinite. See 1st comment of A002496.


LINKS

Robert Israel, Table of n, a(n) for n = 1..10000


FORMULA

A002496(a(n)) mod 10 = 7.


MAPLE

P:=[seq(k mod 10, k=select(isprime, [2, seq(4*i^2+1, i=1..10000)]))]:
seq(`if`(P[i] mod 10 = 7, i, NULL), i=1..nops(P));


CROSSREFS

Cf. A002496, A325437, A325438.
Sequence in context: A320300 A070762 A061208 * A183860 A298109 A184429
Adjacent sequences: A325436 A325437 A325438 * A325440 A325441 A325442


KEYWORD

nonn,base


AUTHOR

Martin Renner, Apr 27 2019


STATUS

approved



