login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A114838
Indices of Fibonacci numbers with 7 distinct prime factors.
3
70, 81, 104, 105, 136, 148, 152, 164, 182, 186, 195, 207, 212, 244, 246, 254, 259, 289, 291, 292, 298, 305, 319, 326, 332, 344, 365, 367, 403, 404, 423, 445, 447, 451, 458, 478, 489, 511, 517, 519, 526, 533, 537, 543, 554, 565, 566, 597, 605, 679, 681, 685, 698, 699, 701, 721, 723, 725, 737, 745, 746, 749, 753, 758, 766, 767, 785, 813, 817, 831, 842, 871, 879, 901, 905, 914, 955, 967, 973, 985, 998, 1006, 1007, 1009, 1043, 1046, 1051, 1133, 1139, 1159, 1167, 1174, 1175, 1177, 1191, 1199, 1207, 1219
OFFSET
1,1
EXAMPLE
a(1)=70 because the 70th Fibonacci number consists of 7 distinct prime factors (i.e., 190392490709135 = 5 x 11 x 13 x 29 x 71 x 911 x 141961).
MATHEMATICA
Select[Range[1220], PrimeNu[Fibonacci[#]]==7&] (* Harvey P. Dale, Sep 18 2020 *)
PROG
(PARI) n=1; while(n<310, if(omega(fibonacci(n))==7, print1(n, ", ")); n++)
CROSSREFS
Column k=7 of A303217.
Sequence in context: A118216 A256082 A345487 * A036191 A165632 A295807
KEYWORD
nonn
AUTHOR
Shyam Sunder Gupta, Feb 19 2006
EXTENSIONS
More terms from Ryan Propper, Apr 26 2006
a(53)-a(98) from Max Alekseyev, Aug 18 2013
STATUS
approved