OFFSET
0,2
COMMENTS
Sequence found by reading the line from 0, in the direction 0, 22, ..., in the square spiral whose vertices are the generalized tridecagonal numbers A195313. Semi-axis opposite to A195318 in the same spiral.
Surface area of a rectangular prism with dimensions n, 2n and 3n. - Wesley Ivan Hurt, Apr 10 2015
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
a(n) = 3*a(n-1)-3*a(n-2)+a(n-3). [Harvey P. Dale, Sep 19 2011]
G.f.: 22*x*(1+x)/(1-x)^3. - Wesley Ivan Hurt, Apr 10 2015
MAPLE
MATHEMATICA
22Range[0, 50]^2 (* or *) LinearRecurrence[{3, -3, 1}, {0, 22, 88}, 50] (* Harvey P. Dale, Sep 19 2011 *)
PROG
(Magma) [22*n^2 : n in [0..40]]; // Vincenzo Librandi, Sep 20 2011
(PARI) vector(50, n, 22*(n-1)^2) \\ Derek Orr, Apr 10 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, Sep 16 2011
STATUS
approved