154]
SUPPLEMENTARY RESEARCHES ON THE PARTITION OF NUMBERS.
507
in which formula [1 — x a ] denotes the irreducible factor of 1—oc?, that is, the factor
which equated to zero gives the prime roots, and p is a root of the equation
[1 — x a ] = 0; the summation of course extends to all the roots of the equation. The
index s extends from s = 1 to s = k; and we have then the portion of the fraction
depending on the denominator [1 — a?\ In the partition of numbers, we have <£# = 1,
and the formula becomes therefore
l/4[i—*“]
where
We may write
= 1 S-3g--
II (s — 1/ p — x
— _l 1 (xd ys-1 _
“■•• + IIO—1)° x) £l-a?]’
XP = coeff. j in t?* 1
Ape-r
fx = II (1 — x m ),
where on has a given series of values the same or different. The indices not divisible
by a may be represented by on, the other indices by cip, we have then
fx — II (1 — x n ) II (1 — a? p ),
where the number of indices ap is equal to k. Hence
/(per*) = n (1 - p n e~ nt ) n (1 - pWe-^y,
or since p is a root of [1 — x a ] = 0, and therefore p a = 1, we have
f (pe~ l ) = n (1 — p n e~ nt ) n (1 — e~ apt );
and it may be remarked that if n = v (mod. a), where v < a, then instead of p n we
may write p v , a change which may be made at once, or at the end of the process of
development.
We have consequently to find
XP = coeff. ^ in t s ~ l ■ P
n (1 - p n e~ 1lt ) H (1 - e~ apt )'
The development of a factor is at once deduced from that of ^ 'A ce ~t > an( ^
l p 6
a series of positive powers of t. The development of a factor ^ _ e - apt i s deduced from
that of
^ - and contains a term involving -. Hence we have
1 — e f t
n (1 - p n e~ nt ) n (1 - e~ apt )
=A —* ¿1 + ^-№-i) +k~i • • • + A_i - + A 0 + &c.,
and thence
XP = P A ~s
t k
64—2