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A075161
Position of A075165(n+1) in A014486.
6
0, 1, 2, 3, 4, 5, 9, 7, 6, 10, 23, 12, 65, 24, 11, 8, 197, 15, 626, 26, 25, 66, 2056, 13, 14, 198, 16, 68, 6918, 29, 23714, 17, 67, 627, 28, 40, 82500, 2057, 199, 27, 290512, 71, 1033412, 200, 30, 6919, 3707852, 31, 37, 38, 628, 629, 13402697, 43, 70, 69, 2058
OFFSET
0,3
COMMENTS
See A075166.
PROG
(Scheme functions showing the essential idea. For the complete source, follow the "Alternative Catalan Orderings" link:)
(define (A075161 n) (CatalanRankGlobal (parenthesization->binexp (primefactorization->parenthesization (1+ n)))))
(define (primefactorization->parenthesization n) (map primefactorization->parenthesization (explist->Nvector! (primefactorization->explist n))))
Function primefactorization->explist maps 1 to (), 2 to (1), 3 to (1 0), 4 to (2), 12 to (1 2), etc.
(define (explist->Nvector! el) (cond ((pair? el) (let loop ((el (cdr el))) (cond ((pair? el) (set-car! el (1+ (car el))) (loop (cdr el))))))) el)
CROSSREFS
Inverse of A075162. a(n) = A075163(n+1)-1. Cf. A075168.
Sequence in context: A346097 A346098 A245821 * A298268 A329044 A222251
KEYWORD
nonn
AUTHOR
Antti Karttunen, Sep 13 2002
STATUS
approved