A037817 Number of i such that d(i) <= d(i-1), where Sum_{i=0..m} d(i)*10^i is the base-10 representation of n.

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

Offset

1,1

Comments

Equivalently, number of nonnegative terms in the first differences of the digits of the decimal representation of n. - Paolo Xausa, Nov 19 2025

Links

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

Maple

A037817 := proc(n)
    a := 0 ;
    dgs := convert(n, base, 10);
    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

A037817[n_] := Count[Differences[IntegerDigits[n]], _?NonNegative];
Array[A037817, 100] (* Paolo Xausa, Nov 19 2025 *)

Prog

(MATLAB) n = 1:10000; a = arrayfun(@(m) sum(diff(num2str(m)-'0')>=0), n); % Chris R. Rehmann, Nov 18 2025

Crossrefs

Cf. A000027, A037833.

Cf. A037809, A037810, A037811, A037812, A037813, A037814, A037815, A037816.

Sequence in context: A011724 A377191 A037807 * A297039 A239705 A025468

Adjacent sequences: A037814 A037815 A037816 * A037818 A037819 A037820

Keyword

nonn,base,easy

Author

Clark Kimberling

Extensions

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

Status

approved