OFFSET
0,22
COMMENTS
Number of i such that d(i)>d(i-1), where Sum{d(i)*2^i: i=0,1,...,m} is base 2 representation of n.
This is the base-2 up-variation sequence; see A297330. - Clark Kimberling, Jan 18 2017
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
Jean-Paul Allouche and Jeffrey Shallit, Sums of digits and the Hurwitz zeta function, in: K. Nagasaka and E. Fouvry (eds.), Analytic Number Theory, Lecture Notes in Mathematics, Vol. 1434, Springer, Berlin, Heidelberg, 1990, pp. 19-30.
Ralf Stephan, Some divide-and-conquer sequences with (relatively) simple ordinary generating functions, 2004.
Ralf Stephan, Table of generating functions.
Eric Weisstein's World of Mathematics, Digit Block.
FORMULA
a(2n) = a(n), a(2n+1) = a(n) + [n is even]. - Ralf Stephan, Aug 21 2003
G.f.: 1/(1-x) * Sum_{k>=0} t^5/(1+t)/(1+t^2) where t=x^2^k. - Ralf Stephan, Sep 10 2003
a(n) = A069010(n) - 1, n>0. - Ralf Stephan, Sep 10 2003
Sum_{n>=1} a(n)/(n*(n+1)) = log(2)/2 + Pi/4 - 1 = A231902 - 1 (Allouche and Shallit, 1990). - Amiram Eldar, Jun 01 2021
MATHEMATICA
Table[SequenceCount[IntegerDigits[n, 2], {0, 1}], {n, 0, 120}] (* Harvey P. Dale, Aug 10 2023 *)
PROG
(Haskell)
a037800 = f 0 . a030308_row where
f c [_] = c
f c (1 : 0 : bs) = f (c + 1) bs
f c (_ : bs) = f c bs
-- Reinhard Zumkeller, Feb 20 2014
(PARI)
a(n) = { if(n == 0, 0, -1 + hammingweight(bitnegimply(n, n>>1))) }; \\ Gheorghe Coserea, Aug 31 2015
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved