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A276501
Smallest number k such that k! has at least n terms in its Zeckendorf representation.
1
0, 3, 5, 5, 7, 8, 9, 9, 9, 11, 11, 14, 14, 14, 14, 14, 15, 17, 18, 18, 18, 18, 18, 20, 20, 20, 20, 20, 21, 21, 21, 22, 22, 26, 26, 26, 26, 26, 26, 26, 28, 28, 31, 31, 32, 32, 32, 34, 34, 34, 34, 34, 34, 35, 35, 35, 36, 38, 38, 38, 38, 38, 38, 38, 41, 41, 41, 41, 43, 43, 43, 43, 47, 47, 47, 47
OFFSET
1,2
COMMENTS
Least k >= 0 such that A007895(A000142(k)) >= n.
Corresponding factorial numbers are 1, 6, 120, 120, 5040, 40320, ...
EXAMPLE
a(4) = 5 because Fibonacci(3) + Fibonacci(6) + Fibonacci(8) + Fibonacci(11) = 2 + 8 + 21 + 89 = 120 = 5!.
PROG
(PARI) a007895(n) = if(n<4, n>0, my(k=2, s, t); while(fibonacci(k++)<=n, ); while(k && n, t=fibonacci(k); if(t<=n, n-=t; s++); k--); s);
a(n) = {my(k = 0); while(a007895(k!) < n, k++); k; }
CROSSREFS
KEYWORD
nonn
AUTHOR
Altug Alkan, Sep 06 2016
STATUS
approved