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 A372960 #68 Jun 04 2025 13:00:50
%S A372960 0,1,1,1,2,1,1,11,1,1,11,1,2,3,1,1,11,11,1,11,1,1,21,1,2,11,1,11,11,1,
%T A372960 1,21,11,1,11,1,1,12,11,1,4,1,11,11,1,11,11,11,1,21,1,1,111,1,1,11,1,
%U A372960 11,21,11,2,11,3,1,11,1,11,31,1,1,11,11,11,12,1,1,21
%N A372960 Concatenation of the exponents in the prime factorization of 2*n-1.
%H A372960 Harvey P. Dale, <a href="/A372960/b372960.txt">Table of n, a(n) for n = 1..1000</a>
%F A372960 a(n) = A037916(2*n-1).
%e A372960 a(8) = 11, because 2*8 - 1 = 15 = 3^1 * 5^1 and the concatenation of the exponents of the prime factorization is 11.
%t A372960 Join[{0},Table[FromDigits[Flatten[IntegerDigits/@FactorInteger[2n-1][[;;,2]]]],{n,2,80}]] (* _Harvey P. Dale_, Jun 04 2025 *)
%Y A372960 Cf. A005408, A037916, A375039.
%K A372960 nonn,base
%O A372960 1,5
%A A372960 _Jean-Marc Rebert_, Aug 02 2024