A355465 Expansion of Sum_{k>=0} (k^k * x/(1 - k^k * x))^k.
1, 1, 17, 19812, 4296562388, 298027622009561768, 10314429455106223377205859112, 256923580408437742134605162130019436138968, 6277101736867794060924264576844540796924098543875220742528
Offset: 0
Keywords
Programs
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PARI
my(N=10, x='x+O('x^N)); Vec(sum(k=0, N, (k^k*x/(1-k^k*x))^k)) -
PARI
a(n) = if(n==0, 1, sum(k=1, n, k^(k*n)*binomial(n-1, k-1)));
Formula
a(n) = Sum_{k=1..n} k^(k*n) * binomial(n-1,k-1) for n > 0.