OFFSET
0,8
COMMENTS
Here 0^0 is defined to be 1. - Wolfdieter Lang, May 27 2018
LINKS
FORMULA
From Wolfdieter Lang, May 22 2018: (Start)
As a triangle: T(n, k) = (n-k)^k * k^(n-k), for n >= 1 and k = 1..n. (End)
EXAMPLE
A(3, 2) = 3^2 * 2^3 = 9*8 = 72.
The array A(n, k) begins:
n\k 0 1 2 3 4 5 6 7 8 9 10 ...
0: 1 0 0 0 0 0 0 0 0 0 0 ...
1: 0 1 2 3 4 5 6 7 8 9 10 ...
2: 0 2 16 72 256 800 2304 6272 16384 41472 102400 ...
3: 0 3 72 729 5184 30375 157464 750141 3359232 14348907 59049000 ...
...
The triangle T(n, k) begins:
n\k 0 1 2 3 4 5 6 7 8 9 ...
0: 1
1: 0 0
2: 0 1 0
3: 0 2 2 0
4: 0 3 16 3 0
5: 0 4 72 72 4 0
6: 0 5 256 729 256 5 0
7: 0 6 800 5184 5184 800 6 0
8: 0 7 2304 30375 65536 30375 2304 7 0
9: 0 8 6272 157464 640000 640000 157464 6272 8 0
... - Wolfdieter Lang, May 22 2018
MATHEMATICA
{{1}}~Join~Table[(#^k k^#) &[n - k], {n, 10}, {k, 0, n}] // Flatten (* Michael De Vlieger, May 24 2018 *)
PROG
(PARI) t1(n)=n-binomial(round(sqrt(2+2*n)), 2)
t2(n)=binomial(floor(3/2+sqrt(2+2*n)), 2)-(n+1)
a(n)=t1(n)^t2(n)*t2(n)^t1(n) \\ Eric Chen, Jun 09 2018
CROSSREFS
KEYWORD
AUTHOR
Henry Bottomley, Jul 02 2001
STATUS
approved