A252750 a(n) = A003961(A005940(n+1)) - 2 * A005940(n+1).

-1, -1, 1, -3, 3, 7, 11, -3, 1, 5, 21, -1, 39, 71, 49, -9, 5, 13, 23, 7, 45, 85, 87, 23, 47, 95, 153, 93, 267, 463, 179, -9, -5, -1, 43, -19, 81, 149, 109, -11, 91, 175, 195, 189, 345, 605, 309, -73, 167, 311, 241, 357, 435, 775, 531, 645, 529, 965, 909, 1151, 1551, 2639, 601, -15, -1, 7, 29, -11, 63, 127, 185, 5, 53, 125, 327, 87, 573, 997, 407, -65, 121, 253, 413, 231

Offset

1,4

Links

Antti Karttunen, Table of n, a(n) for n = 1..8191

Formula

a(n) = A003961(A005940(n+1)) - 2 * A005940(n+1).

a(n) = A252748(A005940(n+1)).

Other identities. For all n >= 1:

sgn(a(n)) = (-1)^(1+A252743(n)).

Prog

(Scheme) (define (A252750 n) (- (A003961 (A005940 (+ 1 n))) (* 2 (A005940 (+ 1 n)))))

Crossrefs

Partial sums: A252751.

Cf. A252743 (characteristic function for positive terms).

Cf. A003961, A005940, A252745, A252748, A249820, A246282.

Sequence in context: A326269 A052989 A358823 * A287274 A305099 A292141

Adjacent sequences: A252747 A252748 A252749 * A252751 A252752 A252753

Keyword

sign

Author

Antti Karttunen, Dec 21 2014

Status

approved