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 A229114 #14 Jul 12 2021 02:10:47 %S A229114 1,8,27,3115,3451,4725,10611,15951,20155,27643,74875,2767675,18390564, %T A229114 27923284,50293331,425018875,897002491,10561657872,15193530235, %U A229114 20939306635,40882585915,80585844499 %N A229114 Numbers k such that antisigma(k) mod k = antisigma(k+1) mod (k+1). %C A229114 Antisigma(k) = A024816(k) = sum of numbers less than k which do not divide k. %C A229114 Numbers k such that A229110(k) = A229110(k+1). %C A229114 For k < 10^8, 2 is the only number such that sigma(k) mod k = sigma(k+1) mod (k+1). %C A229114 a(23) > 10^11. - _Donovan Johnson_, Sep 27 2013 %e A229114 a(3) = 27 because antisigma(27) mod 27 = 338 mod 27 = antisigma(28) mod 28 = 350 mod 28 = 14. %o A229114 (PARI) s=1; r=0; for(n=1, 10^9, n1=n+1; s=s+n1; r1=(s-sigma(n1))%n1; if(r==r1, print(n)); r=r1) /* _Donovan Johnson_, Sep 27 2013 */ %Y A229114 Cf. A024816 (antisigma(n)), A229110 (antisigma(n) mod n). %K A229114 nonn,more %O A229114 1,2 %A A229114 _Jaroslav Krizek_, Sep 26 2013 %E A229114 a(12)-a(22) from _Donovan Johnson_, Sep 27 2013