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A067403
Third column of triangle A067402.
9
1, 5, 45, 405, 3645, 32805, 295245, 2657205, 23914845, 215233605, 1937102445, 17433922005, 156905298045, 1412147682405, 12709329141645, 114383962274805, 1029455660473245, 9265100944259205, 83385908498332845, 750473176484995605, 6754258588364960445, 60788327295284644005
OFFSET
0,2
FORMULA
a(n) = A067402(n+2, 2).
a(n) = 5*9^(n-1) for n>=1, a(0) = 1.
G.f.: (1-4*x)/(1-9*x).
E.g.f.: (4 + 5*exp(9*x))/9. - Stefano Spezia, Sep 30 2022
MAPLE
A067403:=n->5*9^(n-1): 1, seq(A067403(n), n=1..30); # Wesley Ivan Hurt, Apr 09 2017
MATHEMATICA
Join[{1}, NestList[9#&, 5, 30]] (* or *) CoefficientList[Series[ (1-4x)/ (1-9x), {x, 0, 30}], x] (* Harvey P. Dale, Apr 26 2011 *)
PROG
(PARI) Vec((1-4*x)/(1-9*x) + O(x^30)) \\ Michel Marcus, Apr 09 2017
CROSSREFS
Cf. A002001 (second column), A067404 (fourth column), A001019 (powers of 9).
Cf. A067402.
Sequence in context: A125836 A001260 A088505 * A173292 A173558 A022022
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Jan 25 2002
STATUS
approved