login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A050224 1/2-Smith 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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Harvey P. Dale)

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.

Eric Weisstein's World of Mathematics, Smith Numbers

EXAMPLE

88 is a 2^(-1) Smith number because the 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 5 12:24 EST 2021. Contains 349557 sequences. (Running on oeis4.)