The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A216442 Numbers of the form 2^i + 3^j + 5^k, where i, j, k >= 0. 1
3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 18, 20, 22, 24, 26, 27, 28, 29, 30, 32, 33, 34, 35, 36, 38, 40, 42, 44, 46, 48, 50, 53, 54, 56, 58, 60, 64, 66, 68, 70, 72, 74, 78, 83, 84, 86, 87, 88, 90, 92, 94, 96, 98, 102, 107, 108, 110, 114, 116, 118, 122, 127 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Conjecture: Unlike A004050, which has a limited set of integers expressible in more than one way, this set has no such limit.
Number of terms less than or equal to 10^k, k > 0: 8, 56, 238, 615, 1304, 2169, 3606, 5280, 7196, 10414, ....
LINKS
Diego Marques and Alain Togbé, Fibonacci and Lucas numbers of the form 2^a + 3^b + 5^c, Proc. Japan Acad. Ser. A Math. Sci. 89(3): 47-50 (March 2013).
FORMULA
There are O(log^3 x) terms of the sequence up to x. - Charles R Greathouse IV, Oct 28 2022
MATHEMATICA
mx = 140; Union@ Flatten@ Table[2^i + 3^j + 5^k, {i, 0, Log[2, mx]}, {j, 0, Log[3, mx - 2^i]}, {k, 0, Log[5, mx - 2^i - 3^j]}]
CROSSREFS
Cf. A004050.
Sequence in context: A333491 A304816 A298005 * A298296 A099474 A105048
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Sep 20 2012
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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 13 03:16 EDT 2024. Contains 373366 sequences. (Running on oeis4.)