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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A026479 a(n) = least positive integer > a(n-1) and not a(i)*a(j)*a(k) for 1<=i<j<k<n. 6
1, 2, 4, 5, 6, 7, 9, 11, 13, 15, 16, 17, 19, 21, 23, 25, 27, 29, 31, 33, 37, 39, 41, 43, 47, 49, 51, 53, 57, 59, 61, 67, 69, 71, 73, 79, 81, 83, 87, 89, 93, 97, 101, 103, 107, 109, 111, 113, 121, 123, 127, 129, 131, 137, 139, 141, 149, 151, 157, 159, 163 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Robert Price, Table of n, a(n) for n = 1..203

MATHEMATICA

a = {1, 2, 4}; no = {1 2 4};

Do[x = SelectFirst[Range[Last[a] + 1, 1000], ! MemberQ[no, #] &]; AppendTo[a, x]; no = Union[Times @@@ Subsets[a, {3}]], 200]; a (* Robert Price, May 26 2019 *)

CROSSREFS

There are six related sequences: A026477: 1 <= i <  j <  k < n  starting 1,2,3; A026478: 1 <= i <= j <= k < n  starting 1,2,3; A026479: 1 <= i <  j <  k < n  starting 1,2,4; A026480: 1 <= i <= j <= k < n  starting 1,2,4; A026481: 1 <= i <  j <  k < n  starting 1,3,4; A026482: 1 <= i <= j <= k < n  starting 1,3,4.

Sequence in context: A029903 A242871 A026420 * A242788 A026426 A026480

Adjacent sequences:  A026476 A026477 A026478 * A026480 A026481 A026482

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

a(31)-a(61) from Robert Price, May 26 2019

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 September 19 19:27 EDT 2021. Contains 347564 sequences. (Running on oeis4.)