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A295405 a(n) = 1 if n^2+1 is prime, 0 otherwise. 1
1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1

COMMENTS

It is conjectured that n^2+1 is prime infinitely often.

LINKS

Simon Plouffe, Table of n, a(n) for n =1.. 10000

FORMULA

a(n) = A010051(A002522(n)). - Robert Israel, Nov 22 2017

EXAMPLE

With n=1, a(1) = 2, n=2, a(2) = 5, a(3) = 0 since 10 is not prime.

MAPLE

seq(`if`(isprime(n^2+1), 1, 0), n=1..100); # Robert Israel, Nov 22 2017

PROG

(PARI)  a(n)=if(isprime(n^2+1), 1)

for (n = 1, 1000, print(a(n)))

CROSSREFS

Cf. A002496, A002522, A010051.

Sequence in context: A147612 A323509 A197183 * A267001 A141735 A322585

Adjacent sequences:  A295402 A295403 A295404 * A295406 A295407 A295408

KEYWORD

nonn

AUTHOR

Simon Plouffe, Nov 22 2017

STATUS

approved

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Last modified December 12 15:11 EST 2019. Contains 329960 sequences. (Running on oeis4.)