A107054 Denominators of coefficients that satisfy: 5^n = Sum_{k=0..n} c(k)*x^k for n>=0, where c(k) = A107053(k)/a(k).
1, 1, 1, 27, 216, 675000, 72900000, 60036284700000, 491817244262400000, 261371848108054118400000, 3267148101350676480000000000, 932155482929918252063784929280000000000
Offset: 0
Examples
5^0 = 1; 5^1 = 1 + (4)*1; 5^2 = 1 + (4)*2 + (4)*2^2; 5^3 = 1 + (4)*3 + (4)*3^2 + (76/27)*3^3; 5^4 = 1 + (4)*4 + (4)*4^2 + (76/27)*4^3 + (307/216)*4^4. Initial coefficients are: A107053/A107054 = {1, 4, 4, 76/27, 307/216, 380989/675000, 13464073/72900000, 3084163593839/60036284700000, 6109976845914041/491817244262400000, ...}
Crossrefs
Programs
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PARI
{a(n)=denominator(sum(k=0,n,5^k*(matrix(n+1,n+1,r,c,if(r>=c,(r-1)^(c-1)))^-1)[n+1,k+1]))}