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 A143321 #21 Aug 27 2022 10:27:07 %S A143321 15,20,24,35,54,95,98,104,119,135,143,144,160,189,207,209,224,287,319, %T A143321 323,324,351,363,375,377,384,390,459,464,527,539,559,608,779,845,864, %U A143321 875,899,923,989,999,1000,1007,1029,1189,1199,1215,1280,1343,1349,1375 %N A143321 Positive integers k whose sum of distinct prime divisors divides k+1. %H A143321 David A. Corneth, <a href="/A143321/b143321.txt">Table of n, a(n) for n = 1..10000</a> %e A143321 The distinct primes dividing 24 are 2 and 3, since 24 is factored as 2^3 *3^1. 2 + 3 = 5 is a divisor of 24 + 1 = 25. So 24 is a term of this sequence. %p A143321 with(numtheory): a:= proc(n) local f: f:=factorset(n); if `mod`(n+1, add(i, i=f))=0 then n end if end proc: seq(a(n), n=2..1200); # _Emeric Deutsch_, Aug 14 2008 %t A143321 Select[Range[2,1500],Divisible[#+1,Total[FactorInteger[#][[All,1]]]]&] (* _Harvey P. Dale_, Aug 27 2022 *) %o A143321 (PARI) is(n) = n > 1 && (n + 1) % vecsum(factor(n)[, 1]) == 0 \\ _David A. Corneth_, Mar 10 2019 %Y A143321 Cf. A008472, A089352, A143322. %K A143321 nonn %O A143321 1,1 %A A143321 _Leroy Quet_, Aug 07 2008 %E A143321 More terms from _Emeric Deutsch_, Aug 14 2008 %E A143321 More terms from _Max Alekseyev_, Mar 10 2009