A107046 Denominators of the triangle of coefficients T(n,k), read by rows, that satisfy: y^x = Sum_{n=0..x} R_n(y)*x^n for all nonnegative integers x, y, where R_n(y) = Sum_{k=0..n} T(n,k)*y^k and T(n,k) = A107045(n,k)/a(n,k).
1, 1, 1, 4, 2, 4, 108, 18, 12, 27, 6912, 576, 192, 108, 256, 21600000, 360000, 24000, 2700, 1280, 3125, 2332800000, 12960000, 2592000, 291600, 46080, 18750, 46656, 1921161110400000, 1524731040000, 43563744000, 700131600, 15805440, 918750
Offset: 0
Examples
These are the denominators of the triangle that begins: 1; -1,1; 1/4,-1/2,1/4; -1/108,1/18,-1/12,1/27; -11/6912,1/576,1/192,-1/108,1/256; -677/21600000,-61/360000,7/24000,1/2700,-1/1280,1/3125; ... which equals the matrix inverse of triangle A079901(n,k)=n^k: 1; 1,1; 1,2,4; 1,3,9,27; 1,4,16,64,256; 1,5,25,125,625,3125; ...
Crossrefs
Programs
-
PARI
a(n,k)=denominator((matrix(n+1,n+1,r,c,if(r>=c,(r-1)^(c-1)))^-1)[n+1,k+1])
Formula
Denominators of the matrix inverse of triangle A079901(n, k) = n^k.