This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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). 15
 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, 121, 38, 11, 21, 53, 135, 127, 149, 122, 39, 12, 22, 56, 154, 136, 385, 150, 123, 40, 13, 45, 60, 163, 155, 413, 386, 151, 124, 41, 23, 46, 128, 177, 164, 475, 414, 387, 152 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS A. Karttunen, Gatomorphisms (with the complete Scheme source) PROG (Scheme functions showing the general idea:) (define (A072764bi x y) (A080300 (parenthesization->binexp (cons (binexp->parenthesization (A014486 x)) (binexp->parenthesization (A014486 y)))))) (define (A072764 n) (cond ((zero? n) n) (else (A072764bi (A025581 (-1+ n)) (A002262 (-1+ n)))))) CROSSREFS 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. Sequence in context: A268934 A268832 A201566 * A130328 A228993 A083569 Adjacent sequences:  A072761 A072762 A072763 * A072765 A072766 A072767 KEYWORD nonn,tabl AUTHOR Antti Karttunen Jun 12 2002 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 22 22:34 EDT 2019. Contains 328335 sequences. (Running on oeis4.)