

A050224


1/2Smith numbers.


4



88, 169, 286, 484, 598, 682, 808, 844, 897, 961, 1339, 1573, 1599, 1878, 1986, 2266, 2488, 2626, 2662, 2743, 2938, 3193, 3289, 3751, 3887, 4084, 4444, 4642, 4738, 4804, 4972, 4976, 4983, 5566, 5665, 5764, 5797, 5863
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OFFSET

1,1


REFERENCES

McDaniel, W. L., "The existence of infinitely many k Smith numbers", Fibonacci Quarterly, 25(1987), pp. 7680.


LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000
S. S. Gupta, Smith Numbers.
Eric Weisstein's World of Mathematics, Smith Numbers


EXAMPLE

88 is a 2^(1) Smith number because digit sum of 88 i.e. S(88) = 8 + 8=16, which is equal to twice the sum of the digits of its prime factors i.e. 2 * Sp (88) = 2 * Sp (11 * 2 * 2 * 2) = 2 *( 1 + 1 + 2 + 2 + 2) = 16.


MATHEMATICA

snoQ[n_]:=Total[IntegerDigits[n]]==2Total[Flatten[IntegerDigits/@ Flatten[ Table[First[#], {Last[#]}]&/@FactorInteger[n]]]]; Select[Range[ 6000], snoQ] (* Harvey P. Dale, Oct 15 2011 *)


CROSSREFS

Cf. A006753, A050225.
Sequence in context: A226587 A044258 A044639 * A270299 A043522 A044420
Adjacent sequences: A050221 A050222 A050223 * A050225 A050226 A050227


KEYWORD

nonn,base


AUTHOR

Eric W. Weisstein


EXTENSIONS

More terms from Shyam Sunder Gupta, Mar 11 2005


STATUS

approved



