

A255061


Number of steps to reach 0 when starting from (2^n)2 and iterating the map x > x  (number of runs in binary representation of x): a(n) = A255072(A000918(n)).


17



0, 1, 3, 6, 11, 20, 36, 65, 118, 215, 393, 721, 1329, 2463, 4589, 8590, 16142, 30434, 57549, 109114, 207388, 395045, 754027, 1441971, 2762764, 5303466, 10200385, 19656528, 37948281, 73384080, 142115376, 275551755, 534790472, 1038702980, 2018626772, 3924923937, 7634733312
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OFFSET

1,3


COMMENTS

Apart from a(1)=1, gives also the positions of ones in A255054.


LINKS

Table of n, a(n) for n=1..37.


FORMULA

a(n) = A255072(A000918(n)).
a(1) = 0; for n > 1, a(n) = a(n1) + A255071(n1).
Other identities. For all n >= 1:
a(n) = A255062(n)  1.


PROG

(Scheme)
(define (A255061 n) (A255072 (A000918 n)))
(define (A255061 n) (if (= 1 n) 0 (+ (A255061 ( n 1)) (A255071 ( n 1))))) ;; Assuming that A255071 has been already computed, with e.g. the PARIprogram given in that entry.


CROSSREFS

One less than A255062.
First differences: A255071.
Apart from a(1)=1, a subsequence of A255059.
Cf. A000918, A255072, A255054.
Analogous sequences: A218600, A226061.
Sequence in context: A054887 A019302 A119861 * A018075 A125896 A265077
Adjacent sequences: A255058 A255059 A255060 * A255062 A255063 A255064


KEYWORD

nonn


AUTHOR

Antti Karttunen, Feb 14 2015


STATUS

approved



