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 A273672 Permutation of natural numbers induced by looking up the position of fraction A270418(n)/A270419(n) from the full Stern-Brocot tree A007305(n+1)/A047679(n-1). 5
 1, 3, 7, 15, 31, 63, 127, 2, 511, 1023, 2047, 4095, 8191, 16383, 32767, 65535, 131071, 262143, 524287, 1048575, 2097151, 4194303, 8388607, 6, 33554431, 67108863, 4, 268435455, 536870911, 1073741823, 2147483647, 128, 8589934591, 17179869183, 34359738367, 68719476735, 137438953471, 274877906943, 549755813887, 14 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Antti Karttunen, Table of n, a(n) for n = 1..1024 Index entries for sequences that are permutations of the natural numbers PROG (Scheme) (define (A273672 n) (SBtree_index (A270418 n) (A270419 n))) (define (SBtree_index m n) (let loop ((m m) (n n) (z 1)) (cond ((= m n) z) ((< m n) (loop m (- n m) (+ z z))) (else (loop (- m n) n (+ z z 1)))))) (PARI) A065620(n, c=1) = sum(i=0, logint(n+!n, 2), if(bittest(n, i), (-1)^c++<

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Last modified December 7 21:37 EST 2023. Contains 367662 sequences. (Running on oeis4.)