A119490 - OEIS

%I #10 Feb 07 2021 21:07:45

%S 1,2,4,8,16,80,400,10000,250000,48250000,83424250000,1441654464250000,

%T 24913230796704250000,5166032451235389984250000,

%U 1071233655120621702524064250000,3109835221395024747917162004384250000,135419643726614411057926317695276801184250000

%N Sum of the absolute values in row n of A118687.

%H G. C. Greubel, <a href="/A119490/b119490.txt">Table of n, a(n) for n = 0..50</a>

%t A049614[n_]:= n!/Product[Prime[i], {i, 1, PrimePi[n]}];

%t b:= Join[{{1}}, Table[CoefficientList[Product[1 -A049614[k]*x, {k,0,n}], x], {n, 0, 21}]];

%t Table[Sum[Abs[b[[n, j]]], {j, n}], {n, 20}] (* _G. C. Greubel_, Feb 07 2021 *)

%o (Sage)

%o def A049614(n): return factorial(n)/product( nth_prime(j) for j in (1..prime_pi(n)) )

%o def A118687(n,k): return ( product(1 -A049614(k)*x for k in (0..n)) ).series(x, n+2).list()[k]

%o [1]+[sum(abs(A118687(n, k)) for k in (0..n+1)) for n in (0..20)] # _G. C. Greubel_, Feb 07 2021

%Y Cf. A118687.

%K nonn

%O 0,2

%A _Roger L. Bagula_, May 25 2006

%E Terms a(12) onward added by _G. C. Greubel_, Feb 07 2021