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%I #58 Dec 30 2016 05:58:08
%S 0,1,1,1,1,3,4,5,9,9,11,19,23,27,45,87,105,205,401,587,747,1121,1763,
%T 2145,4085,7965,15529,16545,32503,38323,49767,74305,146847,180069,
%U 210427,341745,650987,787109,917411
%N a(0)=0, a(1)=a(2)=a(3)=a(4)=1; thereafter, a(n) = Sum_{k=1..5} a(n-k-(a(n-k) mod 5)).
%H Robert G. Wilson v, <a href="/A259615/b259615.txt">Table of n, a(n) for n = 0..1000</a>
%o (Sage) def first(m):
%o v=[0,1,1,1,1]
%o for i in range(5,m+1):
%o l=0
%o for s in range(1,5+1):
%o l += v[i-s-v[i-s]%5]
%o v.append(l)
%o return v
%o (Ruby) def first(m)
%o v=[0,1,1,1,1]
%o for i in 5..m-1
%o i2=0
%o for j in 1..5
%o r=i-j
%o i2 += v[r-v[r]%5]
%o end
%o v << i2
%o end
%o v
%o end
%Y Cf. A000322, A241154 (sequence obtained without mod 5 in formula).
%K nonn
%O 0,6
%A _Anders Hellström_, Jun 30 2015
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