21092

Appears in sequences

• a(n) = Fibonacci(n+1)^2 + 4*Fibonacci(n).at n=11A057592
• a(n) = floor(product of next n primes / product of next n composite numbers).at n=8A077145
• Bell(n-1) - Fibonacci(n).at n=11A100397
• Number of different values assumed by a/b+c/d as a,b,c,d range between 1 and n.at n=20A119868
• Number of 2-sided strip polyrects with n cells.at n=13A151527
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k nonincreasing even cycles (0<=k<=floor(n/4)). A cycle (b(1), b(2), ...) is said to be increasing if, when written with its smallest element in the first position, it satisfies b(1)<b(2)<b(3)<... . A cycle is said to be even if it has an even number of entries. For example, the permutation (1528)(347)(6) has 1 nonincreasing even cycles.at n=12A186769
• Number of permutations of {1,2,...,n} having no nonincreasing even cycles. A cycle (b(1), b(2), ...) is said to be increasing if, when written with its smallest element in the first position, it satisfies b(1)<b(2)<b(3)<... . A cycle is said to be even if it has an even number of entries.at n=8A186770
• Number of nX3 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=10A241430
• Number of primitive (aperiodic) palindromic structures of length n using an infinite alphabet.at n=17A284841
• Expansion of Product_{i>=1, j>=1} theta_3(x^(i*j)), where theta_3() is the Jacobi theta function.at n=17A308286
• Number of integer partitions of n whose run-sums are not weakly decreasing.at n=38A357878
• Intersection of A361073 and 2 * A361611.at n=22A361215