20160910, 05:47  #1 
"Matthew Anderson"
Dec 2010
Oregon, USA
2^{4}×3^{2}×7 Posts 
A034856/
Hi Math People,
I was exploring oeis.org. This is the Online Encyclopedia of integer sequences. oeis.org/A034856/ Many people have double checked this encyclopedia. I read that for A034856, a(n) reduces to n*(n+3)/2  1. When I work it through, I reach the expression n*(n1)/2 1. Probably I am wrong and the encyclopedia is right. I assume that binomial(n,k) = n!/(k!(nk)!). Can someone else check this expression? Regards, Matt 
20160910, 07:25  #2  
Sep 2003
2585_{10} Posts 
Quote:
Code:
binomial(n+1, 2) + (n − 1) n*(n+1) 2*(n−1) =  +  2 2 n*n + 1*n + 2*n − 2 =  2 n*(n+3) − 2 =  2 n*(n+3) =  − 1 2 

20160910, 14:20  #3 
"Matthew Anderson"
Dec 2010
Oregon, USA
2^{4}·3^{2}·7 Posts 
Thank you GP2. You are correct.
Regards, Matt 