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 A098835 #13 Mar 14 2025 09:36:28 %S A098835 378,438,576,588,636,648,654,666,690,728,762,852,1086,1284,1376,1626, %T A098835 1736,1776,1842,1872,1908,1952,1962,2286,2484,2556,2576,2688,2934, %U A098835 2944,2958,2964,2970,3138,3168,3174,3246,3258,3294,3366,3390,3564,3690,3852 %N A098835 Smith abundant numbers. %H A098835 Amiram Eldar, <a href="/A098835/b098835.txt">Table of n, a(n) for n = 1..10000</a> %H A098835 Shyam Sunder Gupta, <a href="https://doi.org/10.1007/978-981-97-2465-9_4">Smith Numbers</a>, Exploring the Beauty of Fascinating Numbers, Springer (2025) Ch. 4, 127-157. %e A098835 a(1) = 378 because 378 is a Smith number as well as an abundant number. %t A098835 digSum[n_] := Plus @@ IntegerDigits[n]; abSmithQ[n_] := DivisorSigma[1, n] > 2*n && Plus @@ (Last@# * digSum[First@#] & /@ FactorInteger[n]) == digSum[n]; Select[Range[4000], abSmithQ] (* _Amiram Eldar_, Aug 23 2020 *) %Y A098835 Intersection of A005101 and A006753. %K A098835 base,nonn %O A098835 1,1 %A A098835 _Shyam Sunder Gupta_, Oct 10 2004