A370633 Numbers k such that A372041(k) = 3.

1, 2, 4, 5, 11, 14, 31, 32, 35, 47, 70, 79, 80, 86, 89, 91, 104, 109, 127, 149, 161, 170, 182, 185, 194, 196, 226, 242, 260, 283, 289, 302, 311, 316, 317, 319, 338, 350, 355, 361, 362, 373, 392, 413, 433, 472, 490, 496, 499, 500, 506, 517, 518, 520, 524, 530, 568, 574, 593

Offset

1,2

Comments

3 is the smallest positive value occurring in A372041 and occurs when the sum of the squares of the first 2*k+1 primes starting at 3 is a prime.

Links

Table of n, a(n) for n=1..59.

Formula

a(n) = (A160358(n) - 1)/2.

Example

k = 2 is a term since A372041(2) = 3, meaning that the sum of the 2*k+1 = 5 squares of primes starting at 3 is a prime: 3^2 + 5^2 + 7^2 + 11^2 + 13^2 = 373.

Crossrefs

Cf. A133547, A160358, A372041.

Sequence in context: A113733 A294434 A191289 * A256570 A284427 A366702

Adjacent sequences: A370630 A370631 A370632 * A370634 A370635 A370636

Keyword

nonn

Author

Michel Lagneau, May 01 2024

Status

approved