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A198853
a(n) = 5*8^n - 1.
1
4, 39, 319, 2559, 20479, 163839, 1310719, 10485759, 83886079, 671088639, 5368709119, 42949672959, 343597383679, 2748779069439, 21990232555519, 175921860444159, 1407374883553279, 11258999068426239, 90071992547409919, 720575940379279359, 5764607523034234879, 46116860184273879039
OFFSET
0,1
FORMULA
a(n) = 8*a(n-1) + 7.
a(n) = 9*a(n-1) - 8*a(n-2), n > 1.
G.f.: (4+3*x)/((8*x-1)*(x-1)). - R. J. Mathar, Oct 31 2011
E.g.f.: exp(x)*(5*exp(7*x) - 1). - Stefano Spezia, Jun 02 2026
PROG
(Magma) [5*8^n-1: n in [0..30]];
CROSSREFS
Cf. A001018.
Sequence in context: A290559 A360740 A059945 * A093851 A224755 A241075
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Oct 31 2011
STATUS
approved