A139586 Non-Fibonacci numbers with Fibonacci number of divisors.

4, 7, 9, 11, 16, 17, 19, 23, 24, 25, 29, 30, 31, 37, 40, 41, 42, 43, 47, 49, 53, 54, 56, 59, 61, 66, 67, 70, 71, 73, 78, 79, 81, 83, 88, 97, 101, 102, 103, 104, 105, 107, 109, 110, 113, 114, 121, 127, 128, 130, 131, 135, 136, 137, 138

Offset: 1

Author

Omar E. Pol, May 22 2008

Keywords

• easy
• nonn

Comments

A000005(a(n)) is a Fibonacci number.

Examples

			16 is a term because it is not a Fibonacci number and its number of divisors is 5, a Fibonacci number.
		

Crossrefs

Non-Fibonacci numbers: A001690.

Cf. A000005, A000045, A139095, A139587, A139588, A139589, A139590.

Programs

Mathematica

fibs=Fibonacci[Range[15]]; nonfibs=Complement[Range[fibs[[-1]]],fibs]; Select[nonfibs,MemberQ[fibs,DivisorSigma[0,#]]&] (* Harvey P. Dale, Jan 11 2011 *)