33551

Appears in sequences

• Truncated tetrahedral numbers: a(n) = (1/6)*(n+1)*(23*n^2 + 19*n + 6).at n=20A005906
• Solution to a binomial problem together with companion sequence A081016(n-1).at n=5A089508
• a(n) = a(n-1) + a(n-3) + a(n-4) for n > 3, a(0) = -1, a(1) = 1, a(2) = 2, a(3) = 1.at n=24A111569
• Numerator of Sum_{k=1..n} 1/(Fibonacci(k)*Fibonacci(k+2)).at n=10A119996
• Sum of strong primes < 10^n.at n=2A159686
• Number of 5-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero.at n=10A208599
• Numbers n such that n^2 - 1 is the product of four distinct Fibonacci numbers greater than 1.at n=20A242074
• a(n) = F(n)*F(n+1) - (-1)^n, where F = A000045.at n=12A260259
• Expansion of Product_{k>0} 1/(1 + x^k)^(k*5).at n=20A279932
• Take a squarefree semiprime and take the difference of its prime factors. If it is a squarefree semiprime repeat the process. Sequence lists the squarefree semiprimes that generate other squarefree semiprimes only in the first k steps of this process. Case k = 5.at n=14A296812
• Take a squarefree semiprime and take the difference of its prime factors. If it is a squarefree semiprime repeat the process. Sequence lists the squarefree semiprimes that generate other squarefree semiprimes only in the first k steps of this process. Case k = 6.at n=4A296813
• a(n) = Sum_{k=0..floor(n/2)} k^(n-2*k) * Stirling2(n-k,k).at n=10A353288