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A135190
Numbers n that raised to the powers from 1 to k (with k>=1) are multiple of the sum of their digits (n raised to k+1 must not be a multiple). Case k=5.
12
3, 12, 36, 42, 102, 162, 432, 468, 1002, 1026, 1080, 1188, 1215, 1380, 1512, 1620, 1770, 1950, 1980, 2136, 2394, 2460, 2466, 2628, 3210, 3240, 3276, 3492, 3540, 3654, 3816, 3864, 4032, 4050, 4116, 4374, 4680, 4752, 4806, 4860, 4950, 5058, 5238
OFFSET
1,1
FORMULA
Positive integers n such that A195860(n)=6.
EXAMPLE
3^1=3
3^2=9 and 9 is a multiple of 3
3^3=27 -> Sum_digits(27)=9 and 27 is a multiple of 9
3^4=81 -> Sum_digits(81)=9 and 81 is a multiple of 9
3^5=243 -> Sum_digits(243)=9 and 243 is a multiple of 9
3^6=729 -> Sum_digits(729)=18 and 729 is not a multiple of 18
MAPLE
readlib(log10); P:=proc(n, m) local a, i, k, w, x, ok; for i from 1 by 1 to n do a:=simplify(log10(i)); if not (trunc(a)=a) then ok:=1; x:=1; while ok=1 do w:=0; k:=i^x; while k>0 do w:=w+k-(trunc(k/10)*10); k:=trunc(k/10); od; if trunc(i^x/w)=i^x/w then x:=x+1; else if x-1=m then print(i); fi; ok:=0; fi; od; fi; od; end: P(2000, 5);
KEYWORD
nonn,base
AUTHOR
EXTENSIONS
More terms from Max Alekseyev, Sep 24 2011
STATUS
approved