20009

Appears in sequences

• Generalized Pellian with second term equal to 8.at n=10A048695
• List the positions of all digits '1' in the sequence. This is the lexicographically earliest increasing sequence with this property.at n=47A098645
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, -1), (0, -1, 1), (1, 1, -1), (1, 1, 1)}.at n=8A149622
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} whose longest block is of length k (0<=k<=n).at n=38A184182
• Number of zero-sum -2..2 arrays of n elements with first through fourth differences also in -2..2.at n=18A201433
• Irregular array T(n,k) of the numbers of non-extendable (complete) non-self-adjacent simple paths ending at each of a minimal subset of nodes within a square lattice bounded by rectangles with nodal dimensions n and 6, n >= 2.at n=35A213070
• Irregular array T(n,k) of the numbers of non-extendable (complete) non-self-adjacent simple paths ending at each of a minimal subset of nodes within a square lattice bounded by rectangles with nodal dimensions n and 7, n >= 2.at n=40A214373
• n * (11*n^2 + 6*n + 1) / 6.at n=22A215646
• a(n) = Sum_{i=0..n} digsum(i)^4, where digsum(i) = A007953(i).at n=16A231689
• Numbers k such that 7*10^k + 33 is prime.at n=21A274679
• Numbers with digit sum 11 that are multiples of 11.at n=25A283742
• a(n) is the number of integer partitions of n for which the Kimberling index is equal to the index of the seaweed algebra formed by the integer partition paired with its weight.at n=57A318177
• Nonsemiprimes in A306097 = A121707 \ A267999.at n=27A321488
• Products of three distinct strong primes.at n=14A363782
• Number of permutations of [n] whose longest block is of length 2. A block of a permutation is a maximal sequence of consecutive integers which appear in consecutive positions.at n=8A370390