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A158130
121n - 1.
1
120, 241, 362, 483, 604, 725, 846, 967, 1088, 1209, 1330, 1451, 1572, 1693, 1814, 1935, 2056, 2177, 2298, 2419, 2540, 2661, 2782, 2903, 3024, 3145, 3266, 3387, 3508, 3629, 3750, 3871, 3992, 4113, 4234, 4355, 4476, 4597, 4718, 4839, 4960, 5081, 5202
OFFSET
1,1
FORMULA
a(n) = 2*a(n-1) -a(n-2).
G.f.: x*(120+x)/(x-1)^2.
MATHEMATICA
Table[121n-1, {n, 50}]
PROG
(Magma) I:=[120, 241]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..50]];
(PARI) a(n) = 121*n - 1.
CROSSREFS
Sequence in context: A232743 A146950 A028976 * A070856 A211467 A257712
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Mar 13 2009
STATUS
approved