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 A337811 #8 Nov 04 2023 08:04:39 %S A337811 1,5,7,13,17,19,25,26,31,34,35,37,38,41,46,49,59,61,62,65,67,77,78,83, %T A337811 85,89,91,93,97,98,103,107,109,118,122,123,125,127,131,133,134,137, %U A337811 139,143,145,147,149,153,157,170,173,175,177,185,186,189,193,194,195 %N A337811 Numbers k such that the number of distinct prime factors of 2^k - 1 is less than the corresponding count for 2^k + 1. %t A337811 Select[Range[200],PrimeNu[2^#-1]<PrimeNu[2^#+1]&] (* _Harvey P. Dale_, Nov 04 2023 *) %o A337811 (PARI) for(n=1,200,if(omega(2^n-1)<omega(2^n+1),print1(n,", "))) %Y A337811 Cf. A046799, A046800, A067886, A337810, A337812, A337813. %K A337811 nonn %O A337811 1,2 %A A337811 _Hugo Pfoertner_, Sep 23 2020