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A067412
Fourth column of triangle A067410.
7
1, 5, 40, 320, 2560, 20480, 163840, 1310720, 10485760, 83886080, 671088640, 5368709120, 42949672960, 343597383680, 2748779069440, 21990232555520, 175921860444160, 1407374883553280, 11258999068426240
OFFSET
0,2
COMMENTS
The fifth column gives [1,6,60,600,6000,60000,...].
a(n+1) = A157176(A016957(n)). [From Reinhard Zumkeller, Feb 24 2009]
FORMULA
a(n)= A067410(n+3, 3). a(n)= 5*8^(n-1), n>=1, a(0)=1.
G.f.: (1-3*x)/(1-8*x).
E.g.f.: (5*exp(8*x)+3)/8 = exp(4*x)*(cosh(4*x)+sinh(4*x)/4) - Paul Barry, Nov 20 2003
MATHEMATICA
Join[{1}, NestList[8#&, 5, 20]] (* or *) CoefficientList[Series[ (1-3x)/ (1-8x), {x, 0, 20}], x] (* Harvey P. Dale, May 14 2011 *)
CROSSREFS
Cf. A067411 (third column), A067413 (sixth column), A001018 (powers of 8).
Sequence in context: A073505 A145841 A123943 * A355355 A078846 A027259
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Jan 25 2002
STATUS
approved