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A083231
a(n) = (3*5^n + (-3)^n)/4.
1
1, 3, 21, 87, 489, 2283, 11901, 58047, 294609, 1459923, 7338981, 36576807, 183238329, 915128763, 4578832461, 22884596367, 114451679649, 572172304803, 2861119804341, 14304824180727, 71526445426569, 357625253564043
OFFSET
0,2
FORMULA
a(n) = (3*5^n + (-3)^n)/4.
G.f.: (1+x)/((1-5*x)*(1+3*x)).
E.g.f.: (3*exp(5*x) + exp(-3*x))/4.
PROG
(Magma) [(3*5^n+(-3)^n)/4: n in [0..25]]; // Vincenzo Librandi, Jun 29 2011
CROSSREFS
Cf. A083232, A053524 (binomial transform, shifted).
Sequence in context: A253943 A034490 A071351 * A129755 A059826 A108970
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Apr 23 2003
STATUS
approved