A072396 Index of smallest Fibonacci number with n prime factors when counted with multiplicity.

3, 8, 6, 20, 18, 12, 30, 54, 24, 36, 138, 48, 84, 72, 108, 96, 210, 120, 276, 168, 216, 252, 288, 240, 336, 570, 384, 420, 360, 576, 480, 540, 504, 660, 600, 672, 990, 720, 792, 840, 1152, 1140

Offset: 1

Author

Shyam Sunder Gupta, Jul 21 2002

Keywords

• nonn
• more

Comments

1452 < a(43) <= 1596, a(44) = 1296, a(45) = 1368, a(46) = 1080, a(47) = 1200, a(48) <= 1728. - Daniel Suteu, Jan 19 2023

Examples

			a(3) = 6 since the 6th Fibonacci number 8 has 3 prime factors.
		

Links

• Hisanori Mishima, Fibonacci numbers (n = 1 to 100).
• Hisanori Mishima, Fibonacci numbers (n = 101 to 200).
• Hisanori Mishima, Fibonacci numbers (n = 201 to 300).
• Hisanori Mishima, Fibonacci numbers (n = 301 to 400).
• Hisanori Mishima, Fibonacci numbers (n = 401 to 480).

Crossrefs

Cf. A000045, A038575, A072397.

Row n=1 of A303215.

Programs

PARI

a(n) = my(k=1); while (bigomega(fibonacci(k)) != n, k++); k; \\ Michel Marcus, Aug 26 2020

Extensions

a(17)-a(24) from Alois P. Heinz, Apr 10 2018

a(25)-a(42) from Amiram Eldar, Aug 26 2020