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

 

Logo

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!)
A178741 a(1)=2. For a(n)+1, differences must be strictly increasing and consecutive terms are relatively prime 0
2, 3, 5, 8, 13, 19, 26, 35, 46, 59, 73, 88, 105, 124, 145, 167, 190, 217, 246, 277, 309, 343, 379, 416, 457, 499, 542, 587, 633, 680, 729, 779, 830, 883, 937, 992, 1049, 1107, 1166, 1227, 1289, 1352, 1419, 1487, 1556, 1627, 1699, 1772, 1847, 1923, 2000, 2079 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..52.

EXAMPLE

a(5) cannot be 12 because 8 and 12 are not relatively prime

MATHEMATICA

f[s_] := Block[{k = 2 s[[ -1]] - s[[ -2]] + 1}, While[ GCD[k, s[[ -1]]] > 1, k++ ]; Append[s, k]]; Rest@ Nest[f, {2, 2}, 51] (* Robert G. Wilson v, Jun 09 2010 *)

CROSSREFS

Sequence in context: A120761 A355513 A281967 * A308929 A308994 A326469

Adjacent sequences: A178738 A178739 A178740 * A178742 A178743 A178744

KEYWORD

nonn

AUTHOR

J. Lowell, Jun 08 2010

EXTENSIONS

a(11) onwards from Robert G. Wilson v, Jun 09 2010

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 December 9 17:12 EST 2022. Contains 358702 sequences. (Running on oeis4.)