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 A248819 #14 May 29 2016 07:04:39 %S A248819 79,479,2879,4895,26879,79999,644735,799999,2395488,6399839,8598719, %T A248819 63652895,144726608,799999999,935546879,12640160863,15282380799, %U A248819 43687707904,79999999999 %N A248819 Numbers n such that the digits of antisigma(n) end in sigma(n). %C A248819 All the primes of the form 8*10^k-1 for k>0 are terms (A056721). - _Giovanni Resta_, May 29 2016 %e A248819 sigma(4895) = 6480 and antisigma of 4895 is (4895 * 4896) / 2 - sigma(4895) = 11982960 - 6480 = 11976480. %p A248819 with(numtheory): P:=proc(q) local a,n; %p A248819 for n from 1 to q do then a:=ilog10(sigma(n))+1; %p A248819 if sigma(n)=((n*(n+1)/2-sigma(n)) mod 10^a) then print(n); %p A248819 fi; od; end: P(10^9); %Y A248819 Cf. A000230, A024816, A056721. %K A248819 nonn,more,base %O A248819 1,1 %A A248819 _Paolo P. Lava_, Oct 15 2014 %E A248819 a(9)-a(19) from _Giovanni Resta_, May 29 2016