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A067420
Fifth column of triangle A067417.
4
1, 7, 105, 1575, 23625, 354375, 5315625, 79734375, 1196015625, 17940234375, 269103515625, 4036552734375, 60548291015625, 908224365234375, 13623365478515625, 204350482177734375, 3065257232666015625
OFFSET
0,2
FORMULA
a(n) = A067417(n+4, 4).
a(n) = 7*(3*5)^(n-1), n >= 1, a(0)=1.
G.f.: (1-8*x)/(1-15*x).
PROG
(Magma) [Ceiling(7*(3*5)^(n-1)): n in [0..20]]; // Vincenzo Librandi, Oct 02 2011
CROSSREFS
Cf. A067419 (fourth column), A067421 (sixth column), A001024 (powers of 15).
Sequence in context: A093741 A139742 A120049 * A368351 A358957 A131869
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Jan 25 2002
STATUS
approved