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 A061882 #11 May 24 2022 08:09:34 %S A061882 11,10,20,30,40,50,60,70,80,90,109,209,309,409,509,609,709,809,909, %T A061882 10909,20909,30909,40909,50909,60909,70909,80909,90909,1090909, %U A061882 2090909,3090909,4090909,5090909,6090909,7090909,8090909,9090909,109090909 %N A061882 a(n) = Smallest nontrivial number k > 9 such that first (leftmost) digit - second digit + third digit - fourth digit ... of k = n. %C A061882 Starting with 109, this sequence has the same terms as A060982 and A061479. - _Georg Fischer_, May 24 2022 %o A061882 (PARI) a(n) = my(k=1,d=digits(k)); while (sum(k=1, #d, (-1)^(k+1)*d[k]) != n, k++; d=digits(k)); k; \\ _Michel Marcus_, May 24 2022 %Y A061882 Cf. A008593, A051885, A060978-A060980, A060982, A061470-A061479, A061870-A061882. %K A061882 base,nonn,easy %O A061882 0,1 %A A061882 Larry Reeves (larryr(AT)acm.org), May 15 2001 %E A061882 Definition amended by _Georg Fischer_, May 24 2022