A362176 Expansion of e.g.f. exp(x * (1-2*x)).

1, 1, -3, -11, 25, 201, -299, -5123, 3249, 167185, 50221, -6637179, -8846903, 309737689, 769776645, -16575533939, -62762132639, 998072039457, 5265897058909, -66595289781995, -466803466259079, 4860819716300521, 44072310882063157, -383679824152382691

Offset

0,3

Links

Seiichi Manyama, Table of n, a(n) for n = 0..668

Formula

a(n) = a(n-1) - 4*(n-1)*a(n-2) for n > 1.

a(n) = n! * Sum_{k=0..floor(n/2)} (-2)^k / (k! * (n-2*k)!).

Prog

(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(x*(1-2*x))))

Crossrefs

Column k=4 of A362277.

Cf. A115329, A293604, A362177.

Sequence in context: A025529 A124078 A096795 * A160039 A272296 A051925

Adjacent sequences: A362173 A362174 A362175 * A362177 A362178 A362179

Keyword

sign,easy

Author

Seiichi Manyama, Apr 10 2023

Status

approved