A331002 a(n) is the real part of f(n) (as defined in A330779).

0, 0, -2, -2, 1, 1, -2, -2, 2, 2, -3, -3, 3, 3, -2, -2, 3, 3, -4, -4, 2, 2, -4, -4, 4, 4, -3, -3, 5, 5, -2, -2, 6, 6, -4, -4, 4, 4, -5, -5, 5, 5, -4, -4, 5, 5, -6, -6, 3, 3, -6, -6, 6, 6, -5, -5, 6, 6, -4, -4, 6, 6, -7, -7, 3, 3, -8, -8, 4, 4, -7, -7, 7, 7, -6

Offset

0,3

Links

Rémy Sigrist, Table of n, a(n) for n = 0..10000

Rémy Sigrist, PARI program for A331002

Formula

a(2*k+1) = a(2*k) for any k >= 0.

a(2*k) = a(2*k-1) + A330779(2*k) * (-1)^k for any k > 0.

Prog

(PARI) See Links section.

Crossrefs

Cf. A330779.

Sequence in context: A000174 A156268 A053257 * A358234 A349366 A151702

Adjacent sequences: A330999 A331000 A331001 * A331003 A331004 A331005

Keyword

sign

Author

Rémy Sigrist, Jan 05 2020

Status

approved