A063477 a(n) is the sum of the divisors of Fibonacci(n) (A000045).

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

Author

Jason Earls, Jul 28 2001

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..1408 (terms 1..1000 from T. D. Noe using Blair Kelly's data)
• Blair Kelly, Fibonacci and Lucas Factorizations.
• Florian Luca, Arithmetic Functions of Fibonacci Numbers, The Fibonacci Quarterly, Vol. 37, No. 3 (1999), pp. 265-268.

Crossrefs

Cf. A000045, A000203.

Programs

Mathematica

DivisorSigma[1, Fibonacci@Range@40] (* Vladimir Reshetnikov, Nov 13 2015 *)

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

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