cp's OEIS Frontend

A361313 a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-5)*a(5) for n >= 6, with a(1)=0 and a(2)=a(3)=a(4)=a(5)=1.

%I A361313 #22 Mar 16 2023 14:09:46
%S A361313 0,1,1,1,1,0,1,1,2,3,4,8,11,20,31,52,88,143,247,408,700,1184,2017,
%T A361313 3462,5909,10196,17518,30281,52365,90704,157556,273742,476893,831298,
%U A361313 1451603,2537736,4441262,7782934,13650555,23969794,42126241,74105773,130476070
%N A361313 a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-5)*a(5) for n >= 6, with a(1)=0 and a(2)=a(3)=a(4)=a(5)=1.
%C A361313 Shifts left 5 places under the INVERT transform.
%H A361313 J. Conrad, <a href="/A361313/b361313.txt">Table of n, a(n) for n = 1..3000</a>
%e A361313 a(11) = a(1)*a(10) + a(2)*a(9) + a(3)*a(8) + a(4)*a(7) + a(5)*a(6) = 0*3 + 1*2 + 1*1 + 1*1 + 1*0 = 4.
%o A361313 (Python)
%o A361313 def A361313(l):
%o A361313     s = [0, 1, 1, 1, 1][:l]
%o A361313     for n in range(5, l):
%o A361313         s.append(sum([s[k] * s[n-k-1] for k in range(n-4)]))
%o A361313     return s
%Y A361313 Cf. A025250.
%K A361313 nonn,eigen
%O A361313 1,9
%A A361313 _J. Conrad_, Mar 08 2023