268 ADDITION TO MR GLAISHERS PAPER “ PROOF OF STIRLING’S THEOREM.” [677
log (l-fd )
1 + -J writing e ' \ n !, the whole exponent of
e is
We have
(w+i)log (l + -n-i(a + 6 + ...)
1 1 _ 1 3 1_
n + 3.4 n 2 4.6 n 3 5.8 n*
— 2 ( a + & + •••)•
1 . 1 . . 1 1 c
= const. — —f- terms in — , — , &c.
4w rr n 3
l 2+ 3 2+ + (2w+l)
(the constant is in fact = ¿7r 2 , but the value is not required), hence a = const. — —
+ terms in —, —, &c.; as regards b, c, &c., there are no terms in -, but we have
n 2 n 3 W
b = const. + terms in —„, &c., c = const. + terms in , &c. Hence the whole exponent
n 2 n d
of e is
= — n + C + —b terms in \, &c.
12?i n 2
As in Mr Glaisher’s investigation, it is shown that e~ r = V(2tt), and hence neglecting
the terms in &c., the final result is
n 2
_ w -i—L
n??. = \Z(2Tr)n n+ ±e 12M .