A038687 Concatenate i >= 1 and j >= 1, then sort.

11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 71, 72, 73, 74, 75, 76, 77, 78, 79, 81, 82, 83, 84, 85, 86, 87, 88, 89, 91, 92, 93, 94, 95, 96, 97, 98, 99, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112

Offset

1,1

Comments

Numbers with at least two nonzero decimal digits. - Charles R Greathouse IV, Jan 13 2015

Links

Table of n, a(n) for n=1..93.

Formula

a(n) = n + O(log n). - Charles R Greathouse IV, Jan 13 2015

Maple

isA038687 := proc(n)
    local nzdigs, d ;
    nzdigs := 0 ;
    for d in convert(n, base, 10) do
        if d > 0 then
            nzdigs := nzdigs+1 ;
        end if ;
    end do:
    simplify(nzdigs>=2 ) ;
end proc:
for n from 1 to 120 do
    if isA038687(n) then
        printf("%d, ", n) ;
    end if;
end do: # R. J. Mathar, May 25 2023

Mathematica

Select[Range[11, 99], DigitCount[#, 10, 0]==0&] (* Harvey P. Dale, Nov 14 2013 *)

Prog

(PARI) is(n)=n/=10^valuation(n, 10); n>9 \\ Charles R Greathouse IV, Jan 13 2015

Crossrefs

Sequence in context: A178405 A162903 A216589 * A359983 A236403 A293728

Adjacent sequences: A038684 A038685 A038686 * A038688 A038689 A038690

Keyword

nonn,base,easy

Author

N. J. A. Sloane.

Status

approved