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Search: id:A135200
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| A135200 |
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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=15. |
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+0
17
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OFFSET
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1,1
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COMMENT
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Is it the sequence finite?
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EXAMPLE
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3780^1=3780 is multiple of Sum_digits(3780)=18
3780^2=14288400 is multiple of Sum_digits(14288400)=27
...
3780^15=459596801440358960392275509579197612032000000000000000 is a multiple of Sum_digits(459596801440358960392275509579197612032000000000000000)=180
while
3780^16=1737275909444556870282801426209366973480960000000000000000 is not multiple of Sum_digits(1737275909444556870282801426209366973480960000000000000000)=198
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MAPLE
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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(40000, 15);
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CROSSREFS
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Cf. A135186, A135187, A135188, A135189, A135190, A135191, A135192, A135193, A135194, A135195, A135196, A135197, A135198, A135199, A135201, A135202.
Adjacent sequences: A135197 A135198 A135199 this_sequence A135201 A135202 A135203
Sequence in context: A133970 A137790 A108179 this_sequence A107539 A046837 A109183
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KEYWORD
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easy,nonn,base
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AUTHOR
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Paolo P. Lava & Giorgio Balzarotti (ppl(AT)spl.at), Nov 26 2007
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