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 A266094 #23 Jul 24 2018 09:46:32 %S A266094 1,4,13,32,104,228,576,1408,4104,9824,19152,39816,82944,196992,441294, %T A266094 881280,1911168,4539024 %N A266094 a(n) is the sum of the divisors of the smallest number k such that the symmetric representation of sigma(k) has n parts. %C A266094 For more information see A239663 and A239665. %F A266094 a(n) = A000203(A239663(n)). %e A266094 Illustration of the symmetric representation of sigma(9): %e A266094 . %e A266094 . _ _ _ _ _ 5 %e A266094 . |_ _ _ _ _| %e A266094 . |_ _ 3 %e A266094 . |_ | %e A266094 . |_|_ _ 5 %e A266094 . | | %e A266094 . | | %e A266094 . | | %e A266094 . | | %e A266094 . |_| %e A266094 . %e A266094 For n = 3 we have that 9 is the smallest number whose symmetric representation of sigma has three parts: [5, 3, 5], so a(3) = 5 + 3 + 5 = 13, equaling the sum of divisors of 9: sigma(9) = 1 + 3 + 9 = 13. %e A266094 For n = 7 we have that 357 is the smallest number whose symmetric representation of sigma has seven parts: [179, 61, 29, 38, 29, 61, 179], so a(7) = 179 + 61 + 29 + 38 + 29 + 61 + 179 = 576, equaling the sum of divisors of 357: sigma(357) = 1 + 3 + 7 + 17 + 21 + 51 + 119 + 357 = 576. %Y A266094 Cf. A000203, A196020, A235791, A236104, A237048, A237270, A237271, A237591, A237593, A239931-A239934, A239663, A239665, A240062, A245092, A262626. %K A266094 nonn,hard,more %O A266094 1,2 %A A266094 _Omar E. Pol_, Dec 21 2015 %E A266094 a(14)-a(18) from _Omar E. Pol_, Jul 21 2018