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 A131484 #12 Nov 25 2013 02:29:09 %S A131484 44,41005,41040,68263,91907,109736,416325,603954,826987,1122407, %T A131484 1218999,1262079,1533375,1649375,1835584,1935225,1964199,2141888, %U A131484 2562016,2615799,2649352,3021075,3186000,3554880,3863678,4221536,4655805,4925844,5236153,5273100 %N A131484 Numbers n such that A001414(n) divides n+1 and A001414(n+1) divides n. %C A131484 There is remote formal resemblance to amicable pairs. %H A131484 Klaus Brockhaus and Donovan Johnson, <a href="/A131484/b131484.txt">Table of n, a(n) for n = 1..1000</a> (first 126 terms from Klaus Brockhaus) %e A131484 44 = 2*2*11 has sum of prime factors 15, which divides 44 + 1 = 45; 45 = 3*3*5 has sum of prime factors 11, which divides 44. Hence 44 is in the sequence. %o A131484 (PARI) {m=4700000; s=2; for(n=2, m, f=factor(n+1); t=sum(j=1, matsize(f)[1], f[j, 1]*f[j, 2]); if((n+1)%s==0&&n%t==0, print1(n, ",")); s=t)} /* _Klaus Brockhaus_, Jul 30 2007 */ %Y A131484 Cf. A001414 (sum of prime factors of n, with repetition), A063990 (amicable numbers), A130871. %K A131484 nonn %O A131484 1,1 %A A131484 _J. M. Bergot_, Jul 28 2007 %E A131484 Edited and extended by _Stefan Steinerberger_ and _Klaus Brockhaus_, Jul 30 2007