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A211205
n-th derivative of x^(x^(x^(x^(x^x)))) at x=1.
4
1, 1, 2, 9, 56, 480, 5094, 60494, 823528, 12365424, 206078880, 3745686912, 74083090872, 1579529362944, 36165466533000, 884104045301640, 22992315801392064, 633547543117707648, 18439576158792912192, 565162707747635408448, 18194047307015185486080
OFFSET
0,3
LINKS
Robert G. Wilson v and Alois P. Heinz, Table of n, a(n) for n = 0..400
FORMULA
E.g.f.: (x+1)^((x+1)^((x+1)^((x+1)^((x+1)^(x+1))))).
MAPLE
a:= n-> n!*coeff(series(subs(x=x+1, x^(x^(x^(x^(x^x))))), x, n+1), x, n):
seq(a(n), n=0..20);
MATHEMATICA
NestList[ Factor[ D[#1, x]] &, x^x^x^x^x^x, 9] /. (x -> 1) (* or quicker *)
Range[0, 20]! CoefficientList[ Series[(1 + x)^(1 + x)^(1 + x)^(1 + x)^(1 + x)^(1 + x), {x, 0, 20}], x]
KEYWORD
nonn
AUTHOR
STATUS
approved