84840

Appears in sequences

• Triangular array T(n,k) giving number of alternating link diagrams with n >= 0 crossings, k = 0..[n/2] connected components and two external legs.at n=17A062038
• Number of alternating link diagrams with n crossings, 1 connected component and two external legs.at n=5A062386
• Convolution of L(n+1) := A000204(n+1) (Lucas), n>=0, with L(n+3), n>=0.at n=14A067981
• Recamán Fibonacci variation: a(1)=1; a(2)=2; for n > 2, a(n) = a(n-1)+a(n-2)-F(n) if that number is positive and not already in the sequence, otherwise a(n) = a(n-1)+a(n-2)+F(n) where F(n) denotes the n-th Fibonacci number.at n=23A079053
• Numbers that can be expressed as the difference of the squares of primes in exactly nine distinct ways.at n=9A092005
• Triangle T where the g.f. of row n of T^(2n) = (2n^2 + y)^n for n>=0, as read by rows, where T^n denotes the n-th matrix power of T.at n=24A177390
• Array a(m,n) (m>0, n>=0) of quotient of de Bruijn alternating sums of m-th powers of binomial coefficients, listed by ascending antidiagonals.at n=31A257050
• List of numbers k whose consecutive digits increase or decrease by d-1, where d is the number of digits in k.at n=100A292439
• Triangular array read by rows: T(n,k) is the number of ordered pairs of n-permutations that generate a group with exactly k orbits, 0 <= k <= n, n >= 0.at n=41A327547
• a(n) is the smallest number k with exactly n divisors in A033075.at n=18A355078