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A358606 a(n) = Sum_{k=0..floor(n/5)} (-1)^k * (n-4*k)!/(n-5*k)!. 4

%I #15 Nov 28 2022 12:05:33

%S 1,1,1,1,1,0,-1,-2,-3,-4,-3,0,5,12,21,26,21,0,-43,-114,-195,-244,-195,

%T 42,581,1440,2421,2990,2157,-1644,-9955,-22974,-37515,-44248,-24219,

%U 50310,205661,442140,689997,740906,190245,-1534224,-4941355,-9887058,-14429619,-13255900,3510141

%N a(n) = Sum_{k=0..floor(n/5)} (-1)^k * (n-4*k)!/(n-5*k)!.

%H Seiichi Manyama, <a href="/A358606/b358606.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) = (4 * a(n-1) - n * a(n-5) + 1)/5 for n > 4.

%o (PARI) a(n) = sum(k=0, n\5, (-1)^k*(n-4*k)!/(n-5*k)!);

%Y Cf. A358603, A358604, A358605.

%Y Cf. A357570.

%K sign

%O 0,8

%A _Seiichi Manyama_, Nov 23 2022

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Last modified July 14 08:10 EDT 2024. Contains 374291 sequences. (Running on oeis4.)