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A075161 Position of A075165(n+1) in A014486. 6

%I #8 Apr 07 2015 04:26:47

%S 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,

%T 198,16,68,6918,29,23714,17,67,627,28,40,82500,2057,199,27,290512,71,

%U 1033412,200,30,6919,3707852,31,37,38,628,629,13402697,43,70,69,2058

%N Position of A075165(n+1) in A014486.

%C See A075166.

%H Antti Karttunen, <a href="/A075161/b075161.txt">Table of n, a(n) for n = 0..1024</a>

%H A. Karttunen, <a href="http://www.iki.fi/~kartturi/matikka/Nekomorphisms/ACO1.htm">Alternative Catalan Orderings</a> (with the complete Scheme source)

%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>

%o (Scheme functions showing the essential idea. For the complete source, follow the "Alternative Catalan Orderings" link:)

%o (define (A075161 n) (CatalanRankGlobal (parenthesization->binexp (primefactorization->parenthesization (1+ n)))))

%o (define (primefactorization->parenthesization n) (map primefactorization->parenthesization (explist->Nvector! (primefactorization->explist n))))

%o Function primefactorization->explist maps 1 to (), 2 to (1), 3 to (1 0), 4 to (2), 12 to (1 2), etc.

%o (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)

%Y Inverse of A075162. a(n) = A075163(n+1)-1. Cf. A075168.

%K nonn

%O 0,3

%A _Antti Karttunen_, Sep 13 2002

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Last modified April 23 03:30 EDT 2024. Contains 371906 sequences. (Running on oeis4.)