%I A077231
%S A077231 1,6,240,448,138240,225280,402554880,1857945600,1010722406400,
%T A077231 301234913280,5859811786752,55010477998080,9141306387333120000,
%U A077231 7898088718655815680,1017975879293416243200,161212016644168089600
%N A077231 Denominators of coefficients of series expansion of a certain integral 
               in the theory of charged particle beams.
%C A077231 The integral is Integrate[1/Sqrt[Log[y]],{y,1,x}]=Sqrt[Pi]*Erfi[Sqrt[Log[x]] 
               with series expansion Sqrt[x-1]*Sum[c(i)*(x-1)^(i-1),{i,0,19}]. Numerator(c(n))= 
               A077230(n), denominator(c(n))=A077231(n).
%D A077231 M. Reiser, Theory and design of charged particle beams. J. Wiley, N.Y. 
               1994, S. Humphries, Charged particle beams. J. Wiley, N.Y. 1990.
%e A077231 Series expansion is Sqrt[x-1]*(2 + 1/6 (x-1) -7/240 (x-1)^2+ 5/448 (x-1)^3 
               -...), hence a(0)=1, a(1)=6, a(2)=240, a(3)=448, etc.
%Y A077231 Cf. A077230.
%Y A077231 Sequence in context: A099124 A099129 A145180 this_sequence A002022 A065948 
               A052510
%Y A077231 Adjacent sequences: A077228 A077229 A077230 this_sequence A077232 A077233 
               A077234
%K A077231 frac,nonn
%O A077231 0,2
%A A077231 Zak Seidov (zakseidov(AT)yahoo.com), Oct 31 2002