A069530 Smallest multiple of n with digit sum = 11, or 0 if no such number exists.

29, 38, 0, 56, 65, 0, 56, 56, 0, 290, 209, 0, 65, 56, 0, 128, 119, 0, 38, 380, 0, 308, 92, 0, 425, 182, 0, 56, 29, 0, 155, 128, 0, 272, 245, 0, 74, 38, 0, 560, 164, 0, 344, 308, 0, 92, 47, 0, 245, 650, 0, 416, 371, 0, 605, 56, 0, 290, 236, 0, 1037, 434, 0, 128, 65, 0, 335

Offset

1,1

Comments

a(n) = 0 if n is divisible by 3, 1111, 1507, 2849, 3367, 4849, 5291 or 7373. - Robert Israel, Feb 14 2024

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Formula

a(3k) = 0 for k = 1, 2, 3, ....

a(n) = n*A088400(n). - R. J. Mathar, Aug 06 2019

Maple

A069530 := proc(n)
    local m ;
    if modp(n, 3) = 0 then
         0 ;
    else
        for m from 1 do
            if digsum(m*n) = 11 then
                return m*n ;
            end if;
        end do:
    end if;
end proc:
seq(A069530(n), n=1..70) ; # R. J. Mathar, Aug 06 2019

Prog

(PARI) sod(n) = {digs = digits(n); return (sum(i=1, #digs, digs[i])); }
a(n) = {if (n % 3 == 0, return (0)); k = 1; while (sod(k*n) != 11, k++); k; } \\ Michel Marcus, Sep 14 2013

Crossrefs

Cf. A166311, A069521, A069522, A069523, A069524, A069525, A069526, A069527, A069528, A069529.

Sequence in context: A333422 A108272 A121999 * A259032 A087144 A357772

Adjacent sequences: A069527 A069528 A069529 * A069531 A069532 A069533

Keyword

base,nonn

Author

Amarnath Murthy, Apr 01 2002

Extensions

More terms from Sascha Kurz, Apr 08 2002

Status

approved