A037811 Number of i such that d(i) <= d(i-1), where Sum_{i=0..m} d(i)*4^i is the base-4 representation of n.

0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 2, 2, 1, 1, 1, 2, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 2, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 1, 2, 2, 2, 1, 1, 2, 2, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 2, 2, 3

Offset

1,21

Links

Table of n, a(n) for n=1..90.

Maple

A037811 := proc(n)
    a := 0 ;
    dgs := convert(n, base, 4);
    for i from 2 to nops(dgs) do
        if op(i, dgs)<=op(i-1, dgs) then
            a := a+1 ;
        end if;
    end do:
    a ;
end proc: # R. J. Mathar, Oct 16 2015

Crossrefs

Cf. A037827.

Sequence in context: A062245 A062246 A034095 * A091237 A143477 A214774

Adjacent sequences: A037808 A037809 A037810 * A037812 A037813 A037814

Keyword

nonn,base

Author

Clark Kimberling

Extensions

Sign in name corrected by R. J. Mathar, Oct 16 2015

Status

approved