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A195323
a(n) = 22*n^2.
9
0, 22, 88, 198, 352, 550, 792, 1078, 1408, 1782, 2200, 2662, 3168, 3718, 4312, 4950, 5632, 6358, 7128, 7942, 8800, 9702, 10648, 11638, 12672, 13750, 14872, 16038, 17248, 18502, 19800, 21142, 22528, 23958, 25432, 26950, 28512, 30118, 31768, 33462, 35200, 36982, 38808
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
FORMULA
a(n) = 22*A000290(n) = 11*A001105(n) = 2*A033584(n).
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
A195323:=n->22*n^2: seq(A195323(n), n=0..80); # Wesley Ivan Hurt, Apr 10 2015
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