18770

Appears in sequences

• Number of n-polyplets (polyominoes connected at edges or corners); may contain holes.at n=7A030222
• a(n) = prime(n)^2 + 1.at n=32A066872
• Table by antidiagonals of T(n,k) = 2*n*T(n,k-1) - n^2*T(n,k-2) + T(n,k-4) starting with T(n,1) = 1.at n=49A073135
• Numbers n such that d(1)^1 + d(2)^2 + ... + d(p)^p and d(1)^p + d(2)^p-1 +... + d(p)^1 are squares, where d(i), i=1..p, are the digits of n.at n=39A178360
• Number of emirps of length ceiling(n/4)+1 and leading digit 1, 3, 7 or 9 (in sequence).at n=20A220349
• The smallest numbers of every class in a classification of positive numbers (see comment).at n=34A247395
• Number of n X 3 nonnegative integer arrays with upper left 0 and lower right its king-move distance away minus 3 and every value increasing by 0 or 1 with every step right, diagonally se or down.at n=8A253006
• T(n,k)=Number of nXk nonnegative integer arrays with upper left 0 and lower right its king-move distance away minus 3 and every value increasing by 0 or 1 with every step right, diagonally se or down.at n=57A253011
• Number of minimal dominating sets in the n-web graph.at n=7A290381
• Expansion of Product_{1 <= i < j} (1 + x^(i*j)).at n=51A321286
• Numbers sandwiched between two semiprimes, one of which is a square.at n=25A358686