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A103125
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4-Smith Numbers.
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2
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2401, 5010, 7000, 10005, 10311, 10410, 10411, 11060, 11102, 11203, 12103, 13002, 13021, 13101, 14001, 14101, 14210, 20022, 20121, 20203, 20401, 21103, 21112, 21120, 21201, 22040, 22101, 22201, 23030, 30003, 30031, 30320, 31002, 31101
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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REFERENCES
| McDaniel, W.L., "The Existence of infinitely Many k- Smith numbers", Fibonacci Quarterly, 25(1987), pp. 76-80.
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LINKS
| S.S.Gupta, Smith Numbers.
Harvey P. Dale, Table of n, a(n) for n = 1..600
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EXAMPLE
| 2401 is a 4- Smith number because sum of the digits of its prime factors, i.e. Sp (2401) = Sp(7*7*7*7)= 7 + 7 + 7 + 7 = 28 which is equal to 4 times the digit sum of 2401 i.e. 4*S(2401) = 4*(2+4+0+1)=28
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MATHEMATICA
| sn4Q[n_]:=Module[{a=Total[Flatten[IntegerDigits/@(Table[First[#], {Last[ #]}]&/@FactorInteger[n])]], b=4Total[IntegerDigits[n]]}, a==b] (* From Harvey P. Dale, Oct 03 2011 *)
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CROSSREFS
| Cf. A006753.
Sequence in context: A186488 A186487 A043396 * A074384 A016924 A016984
Adjacent sequences: A103122 A103123 A103124 * A103126 A103127 A103128
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KEYWORD
| base,nonn
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AUTHOR
| Shyam Sunder Gupta (guptass(AT)rediffmail.com), Mar 16 2005
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