A104391 3-Smith numbers.

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

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1500 from G. C. Greubel)

Shyam Sunder Gupta, Smith numbers.

Wayne L. McDaniel, The Existence of infinitely Many k-Smith numbers, Fibonacci Quarterly, Vol. 25, No. 1 (1987), pp. 76-80.

Example

402 is a 3-Smith number because the 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