A037801 Number of i such that d(i)<d(i-1), where Sum{d(i)*3^i: i=0,1,...,m} is base 3 representation of n.

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

Offset

1,32

Links

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

Maple

A037801 := proc(n)
    a := 0 ;
    dgs := convert(n, base, 3);
    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 15 2015

Crossrefs

Cf. A007089, A037818.

Sequence in context: A353423 A037907 A365167 * A340219 A260413 A053252

Adjacent sequences: A037798 A037799 A037800 * A037802 A037803 A037804

Keyword

nonn,base

Author

Clark Kimberling

Extensions

Sign in name corrected by R. J. Mathar, Oct 15 2015

Status

approved