31298

Appears in sequences

• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (odd natural numbers), t = (primes).at n=35A025117
• Number of partitions satisfying cn(1,5) + cn(4,5) <= cn(2,5) + cn(3,5).at n=43A039894
• a(n) = Sum_{i=0..n-1} (1 + (-1)^(n-1-i))/2 * Sum_{j=0..i} a(j)*a(i-j) for n > 0, with a(0) = 1.at n=10A085139
• Semiprimes in A103377.at n=20A103397
• Number of non-equivalent (mod D_3) ways to place 4 indistinguishable points on a triangular grid of side n so that no two of them are adjacent.at n=7A239574
• Number of 4Xn arrays containing n copies of 0..4-1 with every element equal to or 1 greater than any north, west or northeast neighbors modulo 4 and the upper left element equal to 0.at n=9A267397