A037823 Number of i such that d(i) > d(i-1), where Sum_{i=0..m} d(i)*8^i is the base-8 representation of n.

0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1

Offset

1,136

Links

Chris R. Rehmann, Table of n, a(n) for n = 1..10000

Example

136 is written as 210 in base 8, and we have 2 inequalities 2>1 and 1>0, so a(136) = 2.

Maple

A037823 := proc(n)
    a := 0 ;
    dgs := convert(n, base, 8);
    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

Mathematica

A037823[n_] := Count[Differences[IntegerDigits[n, 8]], _?Negative];
Array[A037823, 100] (* Paolo Xausa, Jan 26 2026 *)

Prog

(MATLAB) n = 1:10000; a = arrayfun(@(m) sum(diff(dec2base(m, 8)-'0')<0), n); % Chris R. Rehmann, Nov 22 2025

Crossrefs

Cf. A007094, A037806.

Cf. A033264, A037818, A037819, A037820, A037821, A037822, A037824, A037825.

Sequence in context: A064873 A295659 A188436 * A293162 A115790 A025460

Adjacent sequences: A037820 A037821 A037822 * A037824 A037825 A037826

Keyword

nonn,base,easy

Author

Clark Kimberling

Extensions

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

Status

approved