75012

Appears in sequences

• a(n) = Sum_{i=1..floor((n+2)/4)} a(2i-1)*a(n-2i+1), with a(1)=a(2)=1 and a(3)=4.at n=16A024949
• Number of ascents of length at least 2 in all skew Dyck paths of semilength n.at n=43A128751
• Antidiagonal sums of triangular array T defined in A014430: T(j,k) = binomial(j+1, k) - 1 for 1 <= k <= j.at n=21A129696
• a(1) = b(1) = 0; for n > 1, b(n) = b(n-1) + n-1 + a(n-1) and a(n) = a(n-1) + n-1 + b(n).at n=11A152891
• a(n) = Fibonacci(n+7) - Fibonacci(7).at n=18A180672
• s(k)-s(j), where the pairs (k,j) are given by A205857 and A205858, and s(k) denotes the (k+1)-st Fibonacci number.at n=39A205859
• s(k)-s(j), where the pairs (k,j) are given by A205862 and A205863, and s(k) denotes the (k+1)-st Fibonacci number.at n=35A205864
• Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x+497)^2 = y^2.at n=28A207077
• a(n) = A253100(2^n-1).at n=8A253101
• Number of interior points that are the intersections of exactly two chords in the configuration A006561(n).at n=41A292104
• The number of interior points that are intersections of exactly two chords for a 2n-gon where all its vertices are joined by lines (cf. A006561).at n=20A352144