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A104391 3-Smith numbers. 4
402, 510, 700, 1113, 1131, 1311, 2006, 2022, 2130, 2211, 2240, 3102, 3111, 3204, 3210, 3220, 4031, 4300, 4410, 5310, 6004, 6100, 6300, 7031, 7120, 9000, 10034, 10125, 10206, 10251, 10304, 10413, 10521, 10612, 10800, 11033, 11111, 11114, 11116, 11121, 11141 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

McDaniel, W. L., "The Existence of infinitely Many k-Smith numbers", Fibonacci Quarterly, 25(1987), pp. 76-80.

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1500

S. S. Gupta, Smith numbers.

EXAMPLE

402 is a 3-Smith number because sum of the digits of its prime factors, i.e., Sp(402) = Sp(2*3*67)= 2 + 3 + 6 + 7 = 18, which is equal to 3 times the digit sum of 402, i.e., 3*S(402) = 3*(4 + 0 + 2) = 18.

MATHEMATICA

Select[Range[12000], Total[Flatten[IntegerDigits/@Table[#[[1]], {#[[2]]}]&/@ FactorInteger[#]]]/Total[IntegerDigits[#]]==3&] (* Harvey P. Dale, Feb 19 2013 *)

CROSSREFS

Cf. A006753, A104390.

Sequence in context: A097742 A115244 A031518 * A250753 A158312 A237177

Adjacent sequences:  A104388 A104389 A104390 * A104392 A104393 A104394

KEYWORD

nonn,base

AUTHOR

Eric W. Weisstein, Mar 04 2005 and Shyam Sunder Gupta, Mar 11 2005

STATUS

approved

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Last modified March 26 20:49 EDT 2017. Contains 284137 sequences.