57146

Appears in sequences

• Number of unlabeled asymmetric 2-ary cacti having n polygons.at n=13A054358
• (c(p)-2)/p where p runs through the primes and where c(p) denotes the p-th Catalan number = binomial(2*p,p)/(p+1).at n=5A082179
• Number of n X 4 0,1 arrays indicating 2 X 2 subblocks of some larger (n+1) X 5 binary array having a sum of two or less, with rows and columns of the latter in lexicographically nondecreasing order.at n=5A227261
• T(n,k)=Number of nXk 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X(k+1) binary array having a sum of two or less, with rows and columns of the latter in lexicographically nondecreasing order.at n=39A227263
• T(n,k)=Number of nXk 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X(k+1) binary array having a sum of two or less, with rows and columns of the latter in lexicographically nondecreasing order.at n=41A227263