OFFSET
0,2
COMMENTS
Sequence found by reading the line from 0, in the direction 0, 30,..., in the square spiral whose vertices are the generalized 17-gonal numbers. - Omar E. Pol, Jul 03 2014
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
MAPLE
MATHEMATICA
Table[30 n^2, {n, 0, 40}]
CoefficientList[Series[30x (1+x)/(1-x)^3, {x, 0, 50}], x] (* or *) LinearRecurrence[ {3, -3, 1}, {0, 30, 120}, 50] (* Harvey P. Dale, Dec 02 2021 *)
PROG
(Magma) [30*n^2: n in [0..40]];
(PARI) a(n)=30*n^2 \\ Charles R Greathouse IV, Jun 17 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jul 03 2014
EXTENSIONS
G.f. corrected by Bruno Berselli, Jul 03 2014
STATUS
approved