OFFSET
1,2
LINKS
Alois P. Heinz, Rows n = 1..12, flattened
EXAMPLE
For n=4 the A000081(4) = 4 functions and their 4th derivatives at x=1 are x^(x^3)->156, x^(x^x*x)->100, x^(x^(x^2))->80, x^(x^(x^x))->56 => 4th row = [56, 80, 100, 156].
Triangle T(n,k) begins:
: 1;
: 2;
: 9, 12;
: 56, 80, 100, 156;
: 480, 660, 890, 950, 1180, 1360, 1420, 1880, 3160;
: 5094, 6534, 8874, 10848, 10974, 13014, 13314, 14928, 14988, 15114, ...
MAPLE
with(combinat):
F:= proc(n) F(n):= `if`(n<2, [x$n], map(h->x^h, g(n-1, n-1))) end:
g:= proc(n, i) option remember; `if`(n=0 or i=1, [x^n],
`if`(i<1, [], [seq(seq(seq(mul(F(i)[w[t]-t+1], t=1..j)*v,
w=choose([$1..nops(F(i))+j-1], j)), v=g(n-i*j, i-1)), j=0..n/i)]))
end:
T:= n-> sort(map(f-> n!*coeff(series(subs(x=x+1, f)
, x, n+1), x, n), F(n)))[]:
seq(T(n), n=1..7);
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Alois P. Heinz, Sep 04 2012
STATUS
approved