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

1,1

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

Links

Table of n, a(n) for n=1..42.

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).

Example

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

Prog

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

Crossrefs

Cf. A000045, A038575, A072397.

Row n=1 of A303215.

Sequence in context: A225267 A320541 A366612 * A001175 A093725 A347118

Adjacent sequences: A072393 A072394 A072395 * A072397 A072398 A072399

Keyword

nonn,more

Author

Shyam Sunder Gupta, Jul 21 2002

Extensions

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

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

Status

approved