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A063477
a(n) is the sum of the divisors of Fibonacci(n) (A000045).
8
1, 1, 3, 4, 6, 15, 14, 32, 54, 72, 90, 403, 234, 420, 1116, 1536, 1598, 5400, 4332, 12096, 17724, 18000, 28658, 157248, 93062, 122148, 320760, 473760, 514230, 2142720, 1349244, 3391488, 5346540, 5708056, 11924808, 48211200, 24664200
OFFSET
1,3
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1408 (terms 1..1000 from T. D. Noe using Blair Kelly's data)
Florian Luca, Arithmetic Functions of Fibonacci Numbers, The Fibonacci Quarterly, Vol. 37, No. 3 (1999), pp. 265-268.
FORMULA
a(n) = sigma(A000045(n)) = A000203(A000045(n)). - Omar E. Pol, Dec 20 2008
a(n) <= A000045(A000203(n)), with equality if and only if n = 1 or 3 (Luca, 1999). - Amiram Eldar, Jan 12 2022
MATHEMATICA
DivisorSigma[1, Fibonacci@Range@40] (* Vladimir Reshetnikov, Nov 13 2015 *)
PROG
(PARI) j=[]; for(n=1, 50, j=concat(j, sigma(fibonacci(n)))); j
(Sage) [sigma(fibonacci(n), 1) for n in range(1, 38)] # Zerinvary Lajos, Jun 04 2009
CROSSREFS
Sequence in context: A137820 A049892 A346504 * A168219 A129827 A325179
KEYWORD
nonn
AUTHOR
Jason Earls, Jul 28 2001
STATUS
approved