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A069025
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Smallest power of 2 with digital sum (A007953) n, or 0 if no such number exists.
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1
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1, 2, 0, 4, 32, 0, 16, 8, 0, 64, 128, 0, 256, 2048, 0, 0, 0, 0, 4096, 8192, 0, 16384, 0, 0, 65536, 32768, 0, 0, 524288, 0, 1048576, 0, 0, 0, 134217728, 0, 16777216, 0, 0, 67108864, 8388608, 0, 268435456, 0, 0, 4398046511104, 2147483648, 0, 0
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| a(3k)=0. In general about half the entries are nonzero.
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EXAMPLE
| Both 2^4=16 and 2^10=1024 have a digital sum of 7 but 2^4 is the smaller so it is the one presented.
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MATHEMATICA
| a = Table[0, {50}]; Do[b = Plus @@ IntegerDigits[2^n]; If[b < 51 && a[[b]] == 0, a[[b]] = 2^n], {n, 0, 10^4}]; a
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CROSSREFS
| Cf. A007632.
Sequence in context: A167341 A199852 A055978 * A145962 A066442 A171388
Adjacent sequences: A069022 A069023 A069024 * A069026 A069027 A069028
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KEYWORD
| base,nonn
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AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Apr 02 2002
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EXTENSIONS
| Edited by Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 05 2002
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