131225

Appears in sequences

• Triangle read by rows: CP(n,i) for n>=0 and 3n+1 >= i >= 0, gives the absolute value of the coefficients of the chromatic polynomial of C_3 X P_(n+1) factored in the form x(x-1)^i.at n=51A123531
• a(n) = (2^(n+1) + n^2 + n)/2.at n=17A132109