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 A263257 #13 Nov 09 2015 16:08:13 %S A263257 0,1,3,5,7,19,23,27,29,31,35,37,41,43,51,53,57,59,61,65,67,71,73,77, %T A263257 79,223,231,233,237,239,241,249,251,263,267,269,271,277,285,291,293, %U A263257 299,303,315,317,321,327,331,335,337,341,347,349,357,359,369,857,859,1077,1081,1087,1095,1097,1101 %N A263257 a(n) = least number with distance n to the infinite trunk (A259934) of the tree defined by edge-relation A049820(child) = parent. %C A263257 a(n) = least number k for which A263254(k) = n. %C A263257 Also positions of records in A263254, thus the sequence is strictly increasing. %H A263257 Antti Karttunen, <a href="/A263257/b263257.txt">Table of n, a(n) for n = 0..1835</a> %o A263257 (Scheme, three alternatives implementations) %o A263257 (define A263257 (RECORD-POS 0 0 A263254)) ;; Uses _Antti Karttunen_'s IntSeq-library %o A263257 (define (A263257 n) (let loop ((k 0)) (if (= (A263254 k) n) k (loop (+ 1 k))))) %o A263257 (define (A263257 n) (A263255bi n 1)) ;; A263255bi given in A263255. %Y A263257 Cf. A049820, A259934, A263254, A263258. %Y A263257 First column of array A263255. %K A263257 nonn %O A263257 0,3 %A A263257 _Antti Karttunen_, Nov 07 2015