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 A353033 #6 May 07 2022 10:39:33 %S A353033 6,47796,111684,123498,224562,228378,384858,773016,1096824,1174542, %T A353033 2351240,2529414,3320472,3332616,3650376,4605096,4838838,4978476, %U A353033 5014842,5788662,6023928,6302724,7658024,8298978,9287240,9967974,10950024,12677496,14036694,14120360,14927990 %N A353033 Numbers m such that tau(m) = 2 * tau(m - 1) and simultaneously sigma(m) = 2 * sigma(m - 1), where tau(k) = A000005(k) and sigma(k) = A000203(k). %C A353033 Corresponding values of tau(m): 4, 24, 24, 16, 16, 16, 16, 32, 32, 16, 32, 32, 32, ... %C A353033 Corresponding values of sigma(m): 12, 127680, 268128, 274560, 483840, 483840, 855360, 1996800, 2862720, 2472960, ... %e A353033 tau(6) = 4 = 2 * tau(5) = 2 * 2, sigma(6) = 12 = 2 * sigma(5) = 2 * 6. %o A353033 (Magma) [m: m in [2..10^6] | #Divisors(m) eq 2 * #Divisors(m - 1) and &+Divisors(m) eq 2 * &+Divisors(m - 1)] %Y A353033 Cf. A000005 (tau), A000203 (sigma), A054004, A347603, A353034. %K A353033 nonn %O A353033 1,1 %A A353033 _Jaroslav Krizek_, Apr 18 2022