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 A353190 #30 Jun 14 2022 09:59:07 %S A353190 1,2,4,4,8,5,12,8,13,11,20,7,24,17,20,16,32,14,36,17,30,29,44,11,43, %T A353190 35,40,27,56,17,60,32,50,47,56,16,72,53,60,29,80,29,84,47,56,65,92,19, %U A353190 89,56,80,57,104,41,92,47,90,83,116,11,120,89,84,64,110,53,132,77,110,65,140,20,144,107,100 %N A353190 a(n) is the (n-1)st odd number minus the sum of the aliquot parts of n. %C A353190 If n is a power of 2 then a(n) = n. %C A353190 Note that A005408 has offset 0, hence A005408(0) = 1. %F A353190 a(n) = A005408(n-1) - A001065(n). %F A353190 a(n) = A016789(n-1) - A000203(n). - _Michel Marcus_, May 01 2022 %e A353190 For n = 10, the first ten odd numbers are 1, 3, 5, 7, 9, 11, 13, 15, 17, 19. The last of them is A005408(10-1) = 19. On the other hand the sum of the aliquot parts of 10 is 1 + 2 + 5 = 8, so a(10) = 19 - 8 = 11. %t A353190 a[n_] := 3*n - 1 - DivisorSigma[1, n]; Array[a, 75] (* _Amiram Eldar_, May 21 2022 *) %o A353190 (PARI) a(n) = 3*n-1-sigma(n); \\ _Michel Marcus_, May 04 2022 %Y A353190 Partial sums give A354801. %Y A353190 Cf. A000203, A000079, A001065, A005408, A016789. %K A353190 nonn %O A353190 1,2 %A A353190 _Omar E. Pol_, Apr 29 2022