cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A076212 Numbers k such that k and Fibonacci(k) have the same number of prime factors, counted with multiplicity.

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%I A076212 #25 Sep 10 2024 08:44:26
%S A076212 1,3,5,7,9,10,11,13,14,17,22,23,26,29,34,43,47,64,83,94,121,131,137,
%T A076212 359,431,433,449,509,569,571
%N A076212 Numbers k such that k and Fibonacci(k) have the same number of prime factors, counted with multiplicity.
%C A076212 More precisely, numbers n such that Omega(n) = Omega(Fibonacci(n)), where Omega(n) (A001222) denotes the number of prime factors of n, counting multiplicity.
%C A076212 a(31) > 1422, if it exists. - _Amiram Eldar_, Sep 10 2024
%e A076212 9 is a term because 9 and 9th Fibonacci number (i.e., 34) have the same number of prime factors, i.e., 2.
%p A076212 with(numtheory): with(combinat): a:=proc(n) if bigomega(n)=bigomega(fibonacci(n)) then n else fi end: seq(a(n),n=1..150); # _Emeric Deutsch_, Feb 15 2006
%t A076212 Select[Range[150], PrimeOmega[#] == PrimeOmega[Fibonacci[#]] &]
%o A076212 (PARI) is(k) = bigomega(k) == bigomega(fibonacci(k)); \\ _Amiram Eldar_, Sep 10 2024
%Y A076212 Cf. A000045, A001222, A038575.
%K A076212 nonn,more
%O A076212 1,2
%A A076212 _Joseph L. Pe_, Nov 03 2002
%E A076212 a(24) from _Harvey P. Dale_, May 01 2008
%E A076212 Edited by _R. J. Mathar_, Aug 11 2008
%E A076212 More terms from _D. S. McNeil_, Dec 23 2010