A352168 a(n) = Sum_{p+q = 2n, p<=q, p,q prime} (p*q mod 2n).

0, 0, 3, 7, 6, 11, 12, 14, 16, 22, 43, 69, 33, 22, 51, 46, 66, 80, 46, 101, 80, 81, 114, 163, 112, 105, 139, 133, 116, 162, 95, 179, 204, 78, 241, 258, 181, 207, 257, 212, 263, 484, 229, 244, 471, 156, 229, 377, 53, 350, 520, 339, 278, 472, 324, 593, 668, 370, 468, 1092, 244, 275

Offset

1,3

Links

Table of n, a(n) for n=1..62.

Formula

a(n) = Sum_{i=1..n} ( i*(2n-i) mod 2n ) * c(i) * c(2n-i), where c is the prime characteristic (A010051).

Prog

(PARI) a(n) = my(s=0); forprime(q=n, 2*n, if (isprime(p=2*n-q), s += (p*q) % (2*n))); s; \\ Michel Marcus, Mar 07 2022

Crossrefs

Cf. A010051, A338768.

Sequence in context: A377799 A338067 A178242 * A379352 A375021 A070882

Adjacent sequences: A352165 A352166 A352167 * A352169 A352170 A352171

Keyword

nonn

Author

Wesley Ivan Hurt, Mar 06 2022

Status

approved