A147824 Minimum number k for which the digital sum of k*n is 4*n.

0, 4, 4, 13, 22, 139, 133, 427, 1111, 1111, 49999, 40909, 49999, 69223, 357142, 1333333, 3124993, 4705294, 11111111, 31578421, 499999999, 238047619, 409090909, 2169565213, 4166666662, 31999999999, 26923076923, 37037037037, 285713928571, 344824137931

Offset

0,2

Links

Chai Wah Wu, Table of n, a(n) for n = 0..49

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=4*n then ok:=0; print(j); fi; od; od; end: P(100);

Prog

(PARI) a(n) = {my(k = 0); while (sumdigits(k*n) != 4*n, k++); k; }; \\ Michel Marcus, Mar 21 2016

Crossrefs

Cf. A147822, A147823, A147825-A147831.

Sequence in context: A005301 A358683 A099924 * A019081 A219454 A059443

Adjacent sequences: A147821 A147822 A147823 * A147825 A147826 A147827

Keyword

easy,nonn,base

Author

Paolo P. Lava and Giorgio Balzarotti, Nov 14 2008

Extensions

Edited by Charles R Greathouse IV, Nov 01 2009

a(15)-a(29) from Donovan Johnson, Sep 16 2012

Status

approved