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 A072764 #12 Oct 25 2024 19:13:28
%S A072764 0,1,3,2,7,6,4,8,16,14,5,17,19,42,15,9,18,44,51,43,37,10,20,47,126,52,
%T A072764 121,38,11,21,53,135,127,149,122,39,12,22,56,154,136,385,150,123,40,
%U A072764 13,45,60,163,155,413,386,151,124,41,23,46,128,177,164,475,414,387,152
%N A072764 Tabular N X N -> N bijection induced by Lisp/Scheme function 'cons' combining the two planar binary trees/general trees/parenthesizations encoded by A014486(X) and A014486(Y).
%H A072764 <a href="/index/Li#ListFunsOfLisp">Index entries for the sequences induced by list functions of Lisp</a>
%H A072764 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%H A072764 A. Karttunen, <a href="http://www.iki.fi/~kartturi/matikka/Nekomorphisms/gatomorf.htm">Gatomorphisms</a> (with the complete Scheme source)
%o A072764 (Scheme functions showing the general idea:)
%o A072764 (define (A072764bi x y) (A080300 (parenthesization->binexp (cons (binexp->parenthesization (A014486 x)) (binexp->parenthesization (A014486 y))))))
%o A072764 (define (A072764 n) (cond ((zero? n) n) (else (A072764bi (A025581 (-1+ n)) (A002262 (-1+ n))))))
%Y A072764 Inverse permutation: A072765. a(n) = A069770(A072766(n)). Also transpose of A072766, i.e. a(n) = A072766(A038722(n)). The upper triangular region: A072773. Projection functions are A072771 ('car') & A072772 ('cdr'). The sizes of the corresponding Catalan structures: A072768. The first row: A057548, the first column: A072795, diagonal: A083938. Cf. also A080300, A025581, A002262.
%K A072764 nonn,tabl
%O A072764 0,3
%A A072764 _Antti Karttunen_ Jun 12 2002
%E A072764 a(0)=0 prepended by _Sean A. Irvine_, Oct 25 2024