OFFSET
0,2
COMMENTS
For n >= 1, the continued fraction expansion of sqrt(4*a(n)) is [6n; {1, 1, 1, 3n-1, 1, 1, 1, 12n}]. - Magus K. Chu, Sep 17 2022
LINKS
Reply to V. Librandi, A147296 (SeqFan list) - M. F. Hasler, Mar 01 2009
Index entries for linear recurrences with constant coefficients, signature (3, -3, 1).
FORMULA
a(n) = n*(9*n + 2), as conjectured by V. Librandi. - From M. F. Hasler, Mar 01 2009
G.f.: x*(11+7*x)/(1-x)^3. - Jaume Oliver Lafont, Aug 30 2009
a(n) = floor((3*n + 1/3)^2). - Reinhard Zumkeller, Apr 14 2010
MATHEMATICA
Table[n(9n+2), {n, 0, 50}] (* or *) LinearRecurrence[{3, -3, 1}, {0, 11, 40}, 50] (* Harvey P. Dale, Dec 19 2014 *)
PROG
(PARI) A147296(n) = n*(9*n + 2) - M. F. Hasler, Mar 01 2009
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Nov 05 2008
EXTENSIONS
More terms from M. F. Hasler, Mar 01 2009
STATUS
approved