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Search: id:A164778
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| A164778 |
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Numbers n with property that average digit of n^2 is s=6. |
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+0
2
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| 24, 27, 387, 417, 423, 447, 528, 537, 543, 624, 663, 678, 684, 687, 714, 768, 774, 786, 813, 816, 822, 828, 834, 864, 867, 876, 882, 888, 891, 894, 924, 927, 933, 936, 942, 948, 957, 963, 969, 972, 978, 984, 987, 993, 10386, 11313, 11772, 12114, 12186
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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All terms are multiples of 3.
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EXAMPLE
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24^2 = 576 and (5 + 7 + 6)/3 = 6
387^2 = 149769 and (1 + 4 + 9 + 7 + 6 + 9)/6 = 6.
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MATHEMATICA
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s={}; me=6; Do[If[me==Mean[IntegerDigits[n^2]], Print[n]; AppendTo[s, n]], {n, 3, 10^4, 3}]; s
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PROGRAM
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(PARI) dsum(n)={my(s=0); while(n>9, s+=n%10; n\=10); s+n}; forstep(n=3, 1e6, 3, if(dsum(n^2)/#Str(n^2)==6, print1(n", ")))
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CROSSREFS
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Cf. A164770 (s=2), A164771 (s=1), A164772 (s=8), A164773 (s=7), A164774 (s=5), A164776 (s=4).
Sequence in context: A162465 A067193 A095235 this_sequence A030500 A107406 A045668
Adjacent sequences: A164775 A164776 A164777 this_sequence A164779 A164780 A164781
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KEYWORD
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base,nonn,easy
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AUTHOR
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Zak Seidov (zakseidov(AT)yahoo.com), Aug 26 2009
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EXTENSIONS
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Program by Charles R Greathouse IV (charles.greathouse(AT)case.edu), Nov 01 2009
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