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A037834
a(n) = Sum_{i=1..m} |d(i) - d(i-1)|, where Sum_{i=0..m} d(i)*2^i is the base-2 representation of n.
21
0, 1, 0, 1, 2, 1, 0, 1, 2, 3, 2, 1, 2, 1, 0, 1, 2, 3, 2, 3, 4, 3, 2, 1, 2, 3, 2, 1, 2, 1, 0, 1, 2, 3, 2, 3, 4, 3, 2, 3, 4, 5, 4, 3, 4, 3, 2, 1, 2, 3, 2, 3, 4, 3, 2, 1, 2, 3, 2, 1, 2, 1, 0, 1, 2, 3, 2, 3, 4, 3, 2, 3, 4, 5, 4, 3, 4, 3, 2, 3, 4, 5, 4, 5, 6, 5, 4, 3, 4, 5
OFFSET
1,5
COMMENTS
Number of i such that |d(i) - d(i-1)| = 1, where Sum_{i=0..m} d(i)*2^i is the base-2 representation of n.
MAPLE
A037834 := proc(n)
local dgs ;
dgs := convert(n, base, 2);
add( abs(op(i, dgs)-op(i-1, dgs)), i=2..nops(dgs)) ;
end proc: # R. J. Mathar, Oct 16 2015
MATHEMATICA
Table[Total@ Flatten@ Map[Abs@ Differences@ # &, Partition[ IntegerDigits[n, 2], 2, 1]], {n, 90}] (* Michael De Vlieger, May 09 2017 *)
PROG
(Haskell)
a037834 n = sum $ map fromEnum $ zipWith (/=) (tail bs) bs
where bs = a030308_row n
-- Reinhard Zumkeller, Feb 20 2014
(Python)
def A037834(n): return (n^(n>>1)).bit_count()-1 # Chai Wah Wu, Jul 13 2024
CROSSREFS
A005811(n)-1.
Cf. A030308.
Sequence in context: A002819 A357562 A307672 * A212496 A348295 A362598
KEYWORD
nonn,base
STATUS
approved