83980

Appears in sequences

• Number of unrooted triangulations with reflection symmetry of a disk with one internal node and n+3 nodes on the boundary.at n=19A005508
• Alkane (or paraffin) numbers l(12,n).at n=11A018213
• a(n) = Sum_{i=0..2*n} Sum_{j=0..n-1} A026519(j, i).at n=12A026534
• Denominators of continued fraction convergents to sqrt(391).at n=13A041743
• One half of binomial coefficients binomial(2*n-8,9).at n=5A053133
• Twelfth column of Losanitsch's triangle A034851 (formatted as lower triangular matrix).at n=9A062136
• Expansion of (1+x^2*C^2)*C^2, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers, A000108.at n=10A071721
• One half of odd-numbered entries of even-numbered rows of Pascal's triangle A007318.at n=49A091044
• One half of odd-numbered entries of even-numbered rows of Pascal's triangle A007318.at n=50A091044
• Sequence of coefficients of x^(n-3) in marked mesh pattern generating function Q_{n,132}^(0,3,0,0)(x).at n=10A212344
• Number of 9-element subsets of [n+9] having an even sum.at n=11A282077
• Number of n-element subsets of [n+9] having an even sum.at n=11A282085
• a(n) = (20*n)!*(6*n)!*n!/((12*n)!*(10*n)!*(3*n)!*(2*n)!).at n=1A295470
• Number of integer compositions of 2n whose half-alternating sum is 0.at n=10A357641
• a(n) = (10*n)!*(3*n)!*(n/2)!/((6*n)!*(5*n)!*(3*n/2)!*n!).at n=2A364178