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A048474
a(n) = 3*n*2^(n-1) + 1.
4
1, 4, 13, 37, 97, 241, 577, 1345, 3073, 6913, 15361, 33793, 73729, 159745, 344065, 737281, 1572865, 3342337, 7077889, 14942209, 31457281, 66060289, 138412033, 289406977, 603979777, 1258291201, 2617245697, 5435817985
OFFSET
0,2
COMMENTS
Original name: a(n) = T(2, n), array T given by A048472.
Binomial transform of A008486. - Paul Barry, Jul 09 2003
Row sums of triangle A134232. - Gary W. Adamson, Oct 14 2007
FORMULA
From Harvey P. Dale, Jan 29 2012: (Start)
a(n) = 5*a(n-1) - 8*a(n-2) + 4*a(n-3); a(0)=1, a(1)=4, a(2)=13.
G.f.: (-x^2 + x - 1)/((x-1)(2*x-1)^2). (End)
MATHEMATICA
Table[3n 2^(n-1)+1, {n, 0, 30}] (* or *) LinearRecurrence[{5, -8, 4}, {1, 4, 13}, 30] (* Harvey P. Dale, Jan 29 2012 *)
PROG
(Magma) [3*n * 2^(n-1) + 1: n in [0..30]]; // Vincenzo Librandi, Sep 23 2011
(PARI) a(n)=3*n*2^(n-1)+1 \\ Charles R Greathouse IV, Oct 07 2015
CROSSREFS
n-th difference of a(n), a(n-1), ..., a(0) is (3, 6, 9, ...).
Cf. A134232.
Sequence in context: A299111 A324250 A226866 * A054761 A244197 A300985
KEYWORD
nonn,easy
EXTENSIONS
Better description from Paul Barry, Jul 09 2003
STATUS
approved