A037830 Number of i such that d(i) >= d(i-1), where Sum_{i=0..m} d(i)*7^i is the base-7 representation of n.

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

Offset

1,49

Links

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

Maple

A037830 := proc(n)
    a := 0 ;
    dgs := convert(n, base, 7);
    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

A037830[n_] := Count[Differences[IntegerDigits[n, 7]], _?NonPositive];
Array[A037830, 100] (* Paolo Xausa, Jan 26 2026 *)

Prog

(MATLAB) n = 1:10000; a = arrayfun(@(m) sum(diff(dec2base(m, 7)-'0')<=0), n); % Chris R. Rehmann, Nov 10 2025

Crossrefs

Cf. A007093, A037814.

Cf. A033265, A037826, A037827, A037828, A037829, A037831, A037832, A037833.

Sequence in context: A396471 A085021 A060209 * A174353 A319582 A187447

Adjacent sequences: A037827 A037828 A037829 * A037831 A037832 A037833

Keyword

nonn,base,easy

Author

Clark Kimberling

Extensions

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

Status

approved