login

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 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A175921
Period 5: repeat [1, 2, 2, -1, 1].
1
1, 2, 2, -1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1, 1, 1, 2, 2, -1, 1
OFFSET
1,2
MATHEMATICA
PadRight[{}, 120, {1, 2, 2, -1, 1}] (* Harvey P. Dale, Dec 30 2016 *)
PROG
(PARI) a(n)=[1, 1, 2, 2, -1][n%5+1] \\ Charles R Greathouse IV, Mar 12 2017
CROSSREFS
KEYWORD
sign,easy,less
AUTHOR
Jaroslav Krizek, Oct 17 2010
EXTENSIONS
Edited by Joerg Arndt, Sep 16 2013
STATUS
approved