OFFSET
1,2
COMMENTS
The reference gives the sequence without the initial 1 and then it is "alternate 3n+2 and 2n+3".
An alternative solution for this sequence is to consider the first second differences repeat giving 2, 3, 5, 5, 8, 7, 11, 12, 14, 14, 17, 16, 20, 21. - Lorraine Gregory, Ed.D. (lgregory(AT)lssu.edu), Jan 19 2009
REFERENCES
D. Dolan, J. Williamson and M. Muri, Mathematics Activities for Elementary School Teachers: A Problem Solving Approach, Addison Wesley Longman, Inc., NY, Fourth Edition (ISBN 0-201-61321-2), Chapter 1, Activity 2, #9.
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = 2*a(n-2)-a(n-4). G.f.: x*(1+2*x+x^2+x^3)/((1-x)^2*(1+x)^2). - Colin Barker, Mar 28 2012
MAPLE
for n from 0 to 80 do printf(`%d, %d, `, 2*n+1, 3*n+2) od:
MATHEMATICA
nn=50; Riffle[Range[1, 2*nn, 2], 3*Range[0, nn]+2] (* Harvey P. Dale, Jan 16 2013 *)
PROG
(PARI) { for (n=1, 1000, if (n%2, a=n, a=3*n/2 - 1); write("b063914.txt", n, " ", a) ) } [Harry J. Smith, Sep 02 2009]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Nancy Shaffer (nancys(AT)rose.net), Aug 30 2001
EXTENSIONS
Better description from Brian Galebach, Sep 05, 2001
More terms from James A. Sellers, Sep 25 2001
STATUS
approved