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 A219645 #8 Nov 25 2012 23:50:22 %S A219645 0,1,2,4,6,7,9,12,14,17,20,22,25,28,31,33,35,38,41,44,46,49,53,54,56, %T A219645 59,62,65,67,70,74,77,80,83,88,90,93,96,99,101,104,108,111,114,117, %U A219645 122,125,129,133,137,142,143,145,148,151,154,156,159,163,166,169 %N A219645 Greatest inverse of A219642; a(n) = maximal i such that A219642(i) = n. %H A219645 A. Karttunen, <a href="/A219645/b219645.txt">Table of n, a(n) for n = 0..10000</a> %F A219645 a(n) = A219643(n)+A219644(n)-1. %o A219645 (Scheme with _Antti Karttunen_'s Intseq-library, three different variants): %o A219645 (define A219645 (PARTIALSUMS 1 0 (compose-funs A219644 1+))) %o A219645 (define A219645v2 (compose-funs -1+ (LEAST-I-WITH-FUN-I-EQ-N 0 0 A219642) 1+)) ;; Slow. %o A219645 (define (A219645v3 n) (+ (A219643 n) (A219644 n) -1)) %Y A219645 Cf. A219643 for the least inverse. A219644 gives the first differences. %Y A219645 This sequence is based on Fibonacci number system (Zeckendorf expansion): A014417. Analogous sequence for binary system: A173601, for factorial number system: A219655. %K A219645 nonn %O A219645 0,3 %A A219645 _Antti Karttunen_, Nov 24 2012