A214517 - OEIS

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A214517

Differences between the numbers n such that 4n^2 + 1 is prime.

1, 1, 2, 2, 1, 2, 2, 1, 5, 2, 7, 1, 5, 4, 5, 3, 2, 8, 3, 2, 2, 1, 2, 2, 6, 2, 3, 2, 5, 3, 2, 2, 10, 1, 2, 7, 3, 3, 2, 5, 3, 2, 2, 3, 5, 2, 8, 3, 4, 6, 7, 5, 17, 1, 5, 2, 3, 7, 5, 3, 2, 2, 10, 1, 2, 2, 8, 3, 20, 4, 6, 7, 3, 4, 5, 20, 1, 4, 1, 4, 10, 3, 3, 2, 3

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OFFSET

1,3

COMMENTS

Sequence A001912 has the values of n. This sequence is the first differences of A001912.

LINKS

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

FORMULA

a(n) = A214516(n)/2 for n > 1.

MATHEMATICA

Differences[Select[Range[100], PrimeQ[1 + 4*#^2] &, 101]]

CROSSREFS

Cf. A121326 (primes of the form 1+4*n^2), A001912 (values of n).

Sequence in context: A302243 A117535 A270747 * A230594 A072463 A128853

Adjacent sequences: A214514 A214515 A214516 * A214518 A214519 A214520

KEYWORD

nonn

AUTHOR

T. D. Noe, Aug 06 2012

STATUS

approved