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A130156
a(0)=1. a(n) = number of earlier terms of the sequence that divide the n-th Fibonacci number.
2
1, 1, 2, 3, 3, 2, 4, 2, 4, 5, 3, 2, 11, 2, 2, 9, 5, 2, 11, 2, 9, 10, 2, 2, 19, 4, 2, 13, 6, 2, 22, 2, 5, 15, 2, 6, 27, 2, 2, 18, 11, 2, 23, 2, 5, 25, 2, 2, 34, 3, 10, 22, 6, 2, 28, 6, 7, 23, 2, 2, 51, 2, 2, 29, 7, 6, 30, 2, 6, 28, 11, 2, 55, 2, 2, 38, 6, 3, 34, 2, 19, 34, 2, 2, 54, 6, 2, 35, 9, 2
OFFSET
0,3
LINKS
EXAMPLE
The 10th Fibonacci number is 55. Among terms (a(0), a(1),..., a(9)) there are 3 terms (a(0)=1, a(1)=1, a(9)=5) that divide 55, so a(10) = 3.
MAPLE
A130156 := proc(nmax) local a, nfib, anew, i, n; a := [1] ; while nops(a) < nmax do n := nops(a) ; nfib := combinat[fibonacci](n) ; anew :=0 ; for i from 1 to nops(a) do if nfib mod op(i, a) = 0 then anew := anew+1 ; fi ; od ; a := [op(a), anew] ; od ; RETURN(a) ; end: A130156(100) ; # R. J. Mathar, Jun 07 2007
PROG
(PARI)
up_to = 16384;
A130156list(upto_n) = { my(v=vector(1+upto_n), fibo); v[1] = 1; for(n=2, #v, fibo = fibonacci(n-1); v[n] = sum(i=1, n-1, !(fibo%v[i]))); (v); };
v130156 = A130156list(up_to);
A130156(n) = v130156[1+n]; \\ Antti Karttunen, Feb 18 2023
CROSSREFS
Sequence in context: A235343 A236456 A046824 * A139169 A238444 A076742
KEYWORD
nonn,look
AUTHOR
Leroy Quet, May 13 2007
EXTENSIONS
More terms from R. J. Mathar, Jun 07 2007
STATUS
approved