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A198795
7*6^n-1.
1
6, 41, 251, 1511, 9071, 54431, 326591, 1959551, 11757311, 70543871, 423263231, 2539579391, 15237476351, 91424858111, 548549148671, 3291294892031, 19747769352191, 118486616113151, 710919696678911, 4265518180073471, 25593109080440831
OFFSET
0,1
FORMULA
a(n) = 6*a(n-1)+5. a(n) = 7*a(n-1)-6*a(n-2), n>1.
G.f. ( 6-x ) / ( (6*x-1)*(x-1) ). - R. J. Mathar, Oct 30 2011
PROG
(Magma) [7*6^n-1: n in [0..30]]
CROSSREFS
Sequence in context: A196433 A197196 A295117 * A320090 A266425 A194781
KEYWORD
nonn
AUTHOR
Vincenzo Librandi, Oct 30 2011
STATUS
approved