138996

Appears in sequences

• Area of the Pythagorean triangle a = u^2 - v^2 (cf. A096382) when u=3, v=4,4,5,...at n=32A096383
• Expansion of g.f. c(3x)^4, where c(x) is the g.f. of A000108.at n=5A101602
• Riordan array (1, x*c(3x)), c(x) the g.f. of A000108.at n=49A110518
• Number of (n+2) X 6 binary arrays avoiding patterns 001 and 101 in rows and columns.at n=6A202198
• Number of (n+2) X 9 binary arrays avoiding patterns 001 and 101 in rows and columns.at n=3A202201
• Triangle read by rows: T(n,k) is the number of rooted maps with n edges whose core comprises k edges, 1 <= k <= n.at n=21A318106
• Discriminants of totally real cubic fields with 2 associated nonconjugate fields.at n=22A329786
• Numbers k such that the sums of digits of k and 1/k in factorial base (A007623) are equal.at n=40A373084