login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

E.g.f.: exp(-(x + x^2 + x^3 + x^4)).
3

%I #19 May 03 2021 02:13:48

%S 1,-1,-1,-1,1,139,151,-1429,-19039,-170281,517231,12144439,108063649,

%T 294730019,-12338255929,-161010756061,-834576525119,10909293532591,

%U 350211422028511,3176429907556079,-8268487440910399,-816508001025525061,-14017265801126968841,-55997107943920795301

%N E.g.f.: exp(-(x + x^2 + x^3 + x^4)).

%H Seiichi Manyama, <a href="/A334564/b334564.txt">Table of n, a(n) for n = 0..500</a>

%F a(0) = 1 and a(n) = - (n-1)! * Sum_{k=1..min(4,n)} k*a(n-k)/(n-k)!.

%t m = 25; Range[0, m]! * CoefficientList[Series[Exp[-(x + x^2 + x^3 + x^4)], {x, 0, m}], x] (* _Amiram Eldar_, May 03 2021 *)

%o (PARI) N=40; x='x+O('x^N); Vec(serlaplace(exp(-x-x^2-x^3-x^4)))

%Y Column 4 of A334561.

%Y Cf. A193930, A334570.

%K sign

%O 0,6

%A _Seiichi Manyama_, May 06 2020