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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A346676 Numbers expressible as 2^x + 3^y where both x and y are positive integers. 0
 5, 7, 11, 13, 17, 19, 25, 29, 31, 35, 41, 43, 59, 67, 73, 83, 85, 89, 91, 97, 113, 131, 137, 145, 155, 209, 245, 247, 251, 259, 265, 275, 283, 307, 337, 371, 499, 515, 521, 539, 593, 731, 733, 737, 745, 755, 761, 793, 857, 985, 1027, 1033, 1051, 1105, 1241 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All terms have the form 6k +- 1. LINKS FORMULA { A004050 } minus { A000079, A000244 }. PROG (PARI) f(x, y) = 2^x + 3^y; lista(nn) = select(x->(x<=nn), setbinop(f, [1..logint(nn, 2)], [1..logint(nn, 3)])); \\ Michel Marcus, Jul 29 2021 (Python) def aupto(lim): s, pow3 = set(), 3 while pow3 < lim: for j in range(1, (lim-pow3).bit_length()): s.add(2**j + pow3) pow3 *= 3 return sorted(set(s)) print(aupto(1242)) # Michael S. Branicky, Jul 29 2021 CROSSREFS Cf. A000079, A000244, A004050. Sequence in context: A216524 A128824 A098420 * A309726 A093495 A093496 Adjacent sequences: A346673 A346674 A346675 * A346677 A346678 A346679 KEYWORD nonn AUTHOR Keith Backman, Jul 28 2021 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 January 29 17:53 EST 2023. Contains 359925 sequences. (Running on oeis4.)