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A152774
Number of proper divisors of the Fibonacci number A000045(n).
2
0, 0, 1, 1, 1, 3, 1, 3, 3, 3, 1, 14, 1, 3, 7, 7, 1, 15, 3, 15, 7, 3, 1, 71, 5, 3, 15, 15, 1, 63, 3, 15, 7, 3, 7, 159, 7, 7, 7, 63, 3, 63, 1, 31, 31, 7, 1, 335, 7, 47, 7, 15, 3, 127, 15, 95, 31, 7, 3, 959, 3, 7, 31, 63, 7, 63, 7, 31, 31, 127, 3, 1535, 3, 15, 47, 31, 15, 127, 3
OFFSET
1,6
LINKS
FORMULA
a(n) = A000005(A000045(n))-1 = A032741(A000045(n)) = A063375(n)-1.
MATHEMATICA
a[n_] := DivisorSigma[0, Fibonacci[n]] - 1; Array[a, 100] (* Amiram Eldar, Apr 07 2024 *)
PROG
(PARI) a(n) = numdiv(fibonacci(n)) - 1; \\ Amiram Eldar, Apr 07 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Jan 17 2009
STATUS
approved