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A115568
Maximal Fibonacci exponent in prime factorization of n, or 1 if there is no Fibonacci exponent.
3
1, 1, 1, 2, 1, 1, 1, 3, 2, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 2, 1, 3, 2, 1, 1, 1, 5, 1, 1, 1, 2, 1, 1, 1, 3, 1, 1, 1, 2, 2, 1, 1, 1, 2, 2, 1, 2, 1, 3, 1, 3, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 3, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 1, 2, 1, 2, 1, 1, 1, 5, 1, 2, 2, 2
OFFSET
1,4
MATHEMATICA
Module[{fibs=Fibonacci[Range[10]]}, Table[Max[Select[FactorInteger[n][[All, 2]], MemberQ[fibs, #]&]]/.(-\[Infinity]->1), {n, 100}]] (* Harvey P. Dale, Apr 08 2022 *)
PROG
(PARI)
A010056(n) = { my(k=n^2); k+=(k+1)<<2; issquare(k) || (n>0 && issquare(k-8)); } \\ This function from Charles R Greathouse IV, Jul 30 2012
A115568(n) = { my(exps=factorint(n)[, 2], expswith1 = vector(1+length(exps), i, if(1==i, i, exps[i-1]))); vecmax(apply(e -> (A010056(e)*e), expswith1)); }; \\ Antti Karttunen, Jul 23 2017
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Giovanni Teofilatto, Mar 11 2006; revised Mar 13 2006
EXTENSIONS
Corrected by R. J. Mathar, Apr 03 2012
STATUS
approved