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 A209636 Matula-numbers computed for rooted trees encoded by A071162/A071163. 8
 1, 2, 4, 3, 8, 6, 7, 5, 16, 12, 14, 10, 19, 13, 17, 11, 32, 24, 28, 20, 38, 26, 34, 22, 53, 37, 43, 29, 67, 41, 59, 31, 64, 48, 56, 40, 76, 52, 68, 44, 106, 74, 86, 58, 134, 82, 118, 62, 131, 89, 107, 71, 163, 101, 139, 79, 241, 157, 191, 109, 331, 179, 277 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Sequence is injective: Any number occurs at most once, as each plane tree encoded by A071162/A071163 is mapped to a unique non-oriented rooted tree. See also A209637, A209638. Sequence A209638 gives the same terms sorted into ascending order. LINKS Indranil Ghosh (terms 0..1000) & Antti Karttunen, Table of n, a(n) for n = 0..8191 FORMULA a(n) = A127301(A071163(n)) = A209637(A054429(n)). PROG (Scheme) (define (A209636 n) (let loop ((n (* 2 n)) (m 1)) (cond ((< n 2) m) ((even? n) (loop (/ n 2) (* m 2))) (else (loop (/ (- n 1) 2) (A000040 m)))))) (PARI) A209636(n) = { my(n=2*n, m=1); while(n >= 2, if(!(n%2), m*=2, m = prime(m)); n\=2); m; } \\ Antti Karttunen, May 25 2017 (Python) from sympy import prime def a(n):     n = 2*n     m = 1     if n<2: return 1     while n>1:         if n%2==0:             n//=2             m*=2         else:             n=(n - 1)//2             m=prime(m)     return m print([a(n) for n in range(101)]) # Indranil Ghosh, May 25 2017, translated from Antti Karttunen's SCHEME code CROSSREFS Cf. A000040, A054429, A071162, A071163, A127301, A209637, A278541. Sequence in context: A264802 A243493 A127301 * A243491 A271863 A341220 Adjacent sequences:  A209633 A209634 A209635 * A209637 A209638 A209639 KEYWORD nonn,easy,base,look AUTHOR Antti Karttunen, Mar 11 2012 STATUS approved

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Last modified May 9 13:09 EDT 2021. Contains 343742 sequences. (Running on oeis4.)