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.
%I A176175 #23 Jul 13 2025 11:06:14
%S A176175 1,3,5,6,7,10,11,13,14,17,19,22,23,26,29,31,34,37,38,41,43,46,47,53,
%T A176175 58,59,61,62,67,71,73,74,79,82,83,86,89,94,97,101,103,106,107,109,113,
%U A176175 118,122,127,131,134,137,139,142,146,149,151,157,158,163,166,167,173,178,179,181,191,193,194,197,199,202,206,211,214,218,223,226,227,229,233,239,241,251,254
%N A176175 Numbers k such that (2^(k-1) mod k) = number of prime divisors of k (counted with multiplicity).
%C A176175 How is this related to A085118? - _R. J. Mathar_, Jul 02 2025
%F A176175 {k: A001222(k) = A062173(k)}.
%p A176175 for n from 1 to 180 do modp(2^(n-1),n) ; if % = numtheory[bigomega](n) then printf("%d,",n) ; end if; end do: # _R. J. Mathar_, Dec 07 2010
%t A176175 Select[Range[254], PrimeOmega[#] == PowerMod[2, # - 1, #] &] (* _Michael De Vlieger_, Jul 02 2025 *)
%Y A176175 Cf. A001222, A062173.
%K A176175 nonn
%O A176175 1,2
%A A176175 _Juri-Stepan Gerasimov_, Dec 07 2010