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 A284344 #23 Oct 04 2022 12:36:14
%S A284344 1,3,4,7,6,12,8,15,13,8,12,28,14,24,24,31,18,39,20,12,32,36,24,60,31,
%T A284344 42,40,56,30,32,32,63,48,54,48,91,38,60,56,20,42,96,44,84,78,72,48,
%U A284344 124,57,33,72,98,54,120,72,120,80,90,60,48,62,96,104,127,84,144
%N A284344 Sum of the divisors of n that are not divisible by 10.
%H A284344 Seiichi Manyama, <a href="/A284344/b284344.txt">Table of n, a(n) for n = 1..10000</a>
%F A284344 G.f.: Sum_{k>=1} k*x^k/(1 - x^k) - 10*k*x^(10*k)/(1 - x^(10*k)). - _Ilya Gutkovskiy_, Mar 25 2017
%F A284344 Sum_{k=1..n} a(k) ~ (3*Pi^2/40) * n^2. - _Amiram Eldar_, Oct 04 2022
%t A284344 Table[Sum[Boole[Mod[d, 10]>0] d , {d, Divisors[n]}], {n, 100}] (* _Indranil Ghosh_, Mar 25 2017 *)
%t A284344 Table[Total[Select[Divisors[n],Last[IntegerDigits[#]]!=0&]],{n,70}] (* _Harvey P. Dale_, Jun 29 2022 *)
%o A284344 (PARI) for(n=1, 100, print1(sumdiv(n, d, ((d%10)>0)*d), ", ")) \\ _Indranil Ghosh_, Mar 25 2017
%o A284344 (Python)
%o A284344 from sympy import divisors
%o A284344 print([sum([i for i in divisors(n) if i%10]) for n in range(1, 101)]) # _Indranil Ghosh_, Mar 25 2017
%Y A284344 Cf. A261776.
%Y A284344 Cf. Sum of the divisors of n that are not divisible by k: A046913 (k=3), A046897 (k=4), A116073 (k=5), A284326 (k=6), A113957 (k=7), A284341 (k=8), A116607 (k=9), this sequence (k=10).
%K A284344 nonn
%O A284344 1,2
%A A284344 _Seiichi Manyama_, Mar 25 2017