There are exactly four positive integers n such that (n+1)2n+23 is an integer. Compute the largest such n.
n=1; a=((n+1)^2 / (n+23));printa, n; n++; if(n<500, goto1, 0)
The 4 numbers are: 21, 98, 219, 461
The largest n = 461
+142 
