This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A286228 Numbers n such that d(n) = 2^omega(n) + omega(n) where d = A000005 and omega = A001221. 1
 1, 4, 9, 12, 18, 20, 25, 28, 44, 45, 49, 50, 52, 63, 68, 75, 76, 92, 98, 99, 116, 117, 121, 124, 147, 148, 153, 164, 169, 171, 172, 175, 188, 207, 212, 236, 242, 244, 245, 261, 268, 275, 279, 284, 289, 292, 316, 325, 332, 333, 338, 356, 361, 363, 369, 387, 388, 404, 412, 423, 425, 428 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 EXAMPLE 1 is in this sequence because d(1) = 1 is equal to 2^omega(1) + omega(1) = 2^0 + 0 = 1. MATHEMATICA Select[Range@ 432, Function[f, DivisorSigma[0, #] == 2^f + f]@ PrimeNu@ # &] (* Michael De Vlieger, May 04 2017 *) PROG (PARI) isok(n) = numdiv(n) == 2^omega(n) + omega(n); \\ Michel Marcus, May 07 2017 CROSSREFS Supersequence of A001248 and of A054753. Cf. A006127. Sequence in context: A038109 A067259 A060687 * A312863 A312864 A326071 Adjacent sequences:  A286225 A286226 A286227 * A286229 A286230 A286231 KEYWORD nonn AUTHOR Juri-Stepan Gerasimov, May 04 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 13 09:58 EST 2019. Contains 329968 sequences. (Running on oeis4.)