A214516 Differences between the numbers n such that n^2 + 1 is prime.

1, 2, 2, 4, 4, 2, 4, 4, 2, 10, 4, 14, 2, 10, 8, 10, 6, 4, 16, 6, 4, 4, 2, 4, 4, 12, 4, 6, 4, 10, 6, 4, 4, 20, 2, 4, 14, 6, 6, 4, 10, 6, 4, 4, 6, 10, 4, 16, 6, 8, 12, 14, 10, 34, 2, 10, 4, 6, 14, 10, 6, 4, 4, 20, 2, 4, 4, 16, 6, 40, 8, 12, 14, 6, 8, 10, 40, 2

Offset

1,2

Comments

Sequence A005574 has the values of n. This sequence is the first differences of A005574. Note that a(1) is the only odd value.

Links

T. D. Noe, Table of n, a(n) for n = 1..10000

Formula

a(n) = 2*A214517(n) for n > 1.

Mathematica

Differences[Select[Range[100], PrimeQ[1 + #^2] &, 101]]

Crossrefs

Cf. A002496 (primes of the form 1+n^2), A005574 (values of n).

Sequence in context: A065176 A368558 A060267 * A352502 A238004 A048244

Adjacent sequences: A214513 A214514 A214515 * A214517 A214518 A214519

Keyword

nonn

Author

T. D. Noe, Aug 06 2012

Status

approved