login
A083232
a(n) = (3*7^n+(-1)^n)/4.
3
1, 5, 37, 257, 1801, 12605, 88237, 617657, 4323601, 30265205, 211856437, 1482995057, 10380965401, 72666757805, 508667304637, 3560671132457, 24924697927201, 174472885490405, 1221310198432837, 8549171389029857
OFFSET
0,2
COMMENTS
Binomial transform of A053524 (without leading zero).
FORMULA
a(n) = (3*7^n+(-1)^n)/4.
G.f.: (1-x)/((1-7*x)*(1+x)).
E.g.f.: (3*exp(7*x)+exp(-x))/4
PROG
(Magma) [(3*7^n+(-1)^n)/4: n in [0..25]]; // Vincenzo Librandi, Jun 29 2011
(PARI) Vec((1-x)/((1-7*x)*(1+x)) + O(x^40)) \\ Andrew Howroyd, Feb 16 2018
CROSSREFS
Cf. A083233.
Sequence in context: A121141 A331449 A220634 * A236581 A262410 A089303
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Apr 23 2003
STATUS
approved