161005

Appears in sequences

• Number of (n+5)X9 0..1 matrices with each 6X6 subblock idempotent.at n=19A224573
• Begin with a(0) = 3. Let a(n) for n > 0 be the smallest positive integer not yet in the sequence which forms part of a Primitive Pythagorean Triple (PPT) when paired with a(n-1).at n=25A239356
• a(n) = Sum_{k=0..n} binomial(k+4,4) * binomial(2*k,2*n-2*k).at n=8A382471