The OEIS is supported by the many generous donors to the OEIS Foundation.

 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 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A285494 Numbers k such that digit sum of k = number of distinct prime factors of k. 4
 20, 30, 102, 120, 200, 300, 1002, 1200, 2000, 2001, 2002, 3000, 3010, 10001, 10002, 10011, 10030, 10120, 11001, 11020, 11110, 12000, 20000, 20001, 21010, 30000, 30030, 30100, 100001, 100030, 100101, 100130, 100210, 100300, 101001, 101101, 101200, 102102, 110001, 110200 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Giovanni Resta, Table of n, a(n) for n = 1..10000 MATHEMATICA Select[Range[2, 10000], Total[IntegerDigits[#]]==Length[FactorInteger[#]]&] (* or *) nd = 10; s = 1; Sort@ Flatten@ Reap[ While[ Times @@ Prime[ Range@ s] < 10^nd, pa = IntegerPartitions[s, {nd}, Range[0, 9]]; Do[Sow@ Select[ FromDigits /@ Permutations[p], PrimeNu[#] == s &], {p, pa}]; s++]][[2, 1]] (* terms < 10^10, Giovanni Resta, Apr 21 2017 *) PROG (PARI) isok(n) = sumdigits(n) == omega(n); \\ Michel Marcus, Apr 20 2017 CROSSREFS Cf. A001221, A007953, A057531, A057532, A050689, A070274, A070275, A063737, A067077. Sequence in context: A008444 A268984 A066214 * A120210 A181639 A166631 Adjacent sequences: A285491 A285492 A285493 * A285495 A285496 A285497 KEYWORD nonn,base AUTHOR Jonathan Frech, Apr 19 2017 EXTENSIONS More terms from Michel Marcus, Apr 20 2017 STATUS approved

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

Last modified December 7 01:40 EST 2022. Contains 358649 sequences. (Running on oeis4.)