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 A337177 #22 Feb 03 2021 23:40:01
%S A337177 0,3,4,5,6,12,8,15,10,18,12,28,14,24,24,27,18,39,20,42,32,36,24,60,26,
%T A337177 42,40,56,30,72,32,63,48,54,48,85,38,60,56,90,42,96,44,84,78,72,48,
%U A337177 124,50,93,72,98,54,120,72,120,80,90,60,168,62,96,104,119,84,144,68,126
%N A337177 Sum of the divisors d of n such that d is not equal to n/d.
%C A337177 a(n) = n+1 iff n is prime or n is the square of a prime (A000430). - _Bernard Schott_, Jan 29 2021
%F A337177 a(n) = Sum_{d|n} d * (1 - [d = n/d]), where [ ] is the Iverson bracket.
%F A337177 a(n) = sigma(n) - A037213(n). - _David A. Corneth_, Jan 30 2021
%t A337177 Table[Sum[k*(1 - KroneckerDelta[k, n/k]) (1 - Ceiling[n/k] + Floor[n/k]), {k, n}], {n, 80}]
%o A337177 (PARI) a(n) = sumdiv(n, d, d*(d!=n/d)); \\ _Michel Marcus_, Jan 29 2021
%o A337177 (PARI) a(n) = sigma(n) - issquare(n)*sqrtint(n) \\ _David A. Corneth_, Jan 30 2021
%Y A337177 Cf. A000203, A037213 (with equal instead of not equal).
%K A337177 nonn,easy
%O A337177 1,2
%A A337177 _Wesley Ivan Hurt_, Jan 28 2021