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 A172969 #12 Apr 09 2024 08:09:32
%S A172969 3,27,51,62,74,91,99,115,123,146,187,206,235,267,274,278,291,351,355,
%T A172969 362,386,403,411,422,427,451,459,494,538,584,665,667,721,723,746,763,
%U A172969 771,824,843,854,866,875,926,955,987,1003,1027,1034,1057,1070,1082
%N A172969 Numbers k such that 3*A000005(k) = 2*A000005(k+1).
%H A172969 Amiram Eldar, <a href="/A172969/b172969.txt">Table of n, a(n) for n = 1..10000</a>
%F A172969 {k: 3*tau(k) = 2*tau(k+1)}.
%p A172969 for n from 1 to 1100 do if 3*numtheory[tau](n) = 2*numtheory[tau](n+1) then printf("%d,",n) ; end if; end do:
%t A172969 Select[Range[1200], 3*DivisorSigma[0, #] == 2*DivisorSigma[0, # + 1] &] (* _Amiram Eldar_, Apr 09 2024 *)
%o A172969 (PARI) is(n) = 3 * numdiv(n) == 2 * numdiv(n+1); \\ _Amiram Eldar_, Apr 09 2024
%Y A172969 Subsequence of A074775.
%Y A172969 Cf. A000005, A172624.
%K A172969 nonn
%O A172969 1,1
%A A172969 _Juri-Stepan Gerasimov_, Nov 21 2010