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A147830
Minimum number k for which the digital sum of k*n is 10*n.
2
0, 19, 199, 1333, 17497, 199999, 1333333, 12842857, 374999986, 1111111111, 199999999999, 1090909090909, 4999999999999, 46076923076923, 571427857142857, 13333333333333333, 124999999999999993, 588235235294117647, 11111111111111111111, 157894731578947368421
OFFSET
0,2
MAPLE
P:=proc(i) local j, k, n, ok, w; for n from 0 by 1 to i do j:=-1; ok:=1; while ok=1 do j:=j+1; w:=0; k:=n*j; while k>0 do w:=w+k-(trunc(k/10)*10); k:=trunc(k/10); od; if w=10*n then ok:=0; print(j); fi; od; od; end: P(100);
PROG
(PARI) a(n) = {my(k = 0); while (sumdigits(k*n) != 10*n, k++); k; }; \\ Michel Marcus, Mar 21 2016
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
EXTENSIONS
Edited by Charles R Greathouse IV, Nov 01 2009
a(6)-a(10) from Donovan Johnson, Sep 16 2012
a(11)-a(19) from Chai Wah Wu, Mar 20 2016
STATUS
approved