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A053410
a(1) = 0, a(2) = 16, a(2n+1) = 10*a(2n) - a(2n-1), a(2n) = 10*a(2n-1) - a(2n-2) + 16.
2
0, 16, 160, 1600, 15840, 156816, 1552320, 15366400, 152111680, 1505750416, 14905392480, 147548174400, 1460576351520, 14458215340816, 143121577056640, 1416757555225600, 14024453975199360, 138827782196768016
OFFSET
1,2
REFERENCES
O. Bottema: Verscheidenheden XXVI. Het vraagstuk van Malfatti, Euclides 25 (1949-50), pp. 144-149. [in Dutch].
O. Bottema, The Malfatti problem (translation of Het vraagstuk van Malfatti), Forum Geom. 1 (2001) 43-50.
FORMULA
a(n) = 10*a(n-1) - 10*a(n-3) + a(n-4).
G.f.: -16*x^2/((x-1)*(x+1)*(x^2-10*x+1)). - Colin Barker, Jun 24 2012
MATHEMATICA
LinearRecurrence[{10, 0, -10, 1}, {0, 16, 160, 1600}, 50] (* G. C. Greubel, May 25 2018 *)
PROG
(PARI) x='x+O('x^30); concat([0], Vec(-16*x^2/((x-1)*(x+1)*(x^2-10*x+1)))) \\ G. C. Greubel, May 25 2018
(Magma) I:=[0, 16, 160, 1600]; [n le 4 select I[n] else 10*Self(n-1) - 10*Self(n-3) +Self(n-4): n in [1..30]]; // G. C. Greubel, May 25 2018
CROSSREFS
Cf. A001078.
Sequence in context: A038846 A079767 A079768 * A225591 A197677 A197535
KEYWORD
easy,nonn
AUTHOR
Antreas P. Hatzipolakis (xpolakis(AT)otenet.gr), Jan 09 2000
EXTENSIONS
More terms from James A. Sellers, Jan 10 2000
STATUS
approved