21304

Appears in sequences

• Positive numbers k such that k and 2*k are anagrams in base 6 (written in base 6).at n=23A023064
• Molien series for group Gamma_{3,0}(2).at n=23A027632
• Number of permutations P of {1,2,...,n} such that P(1)=1 and |P^-1(i+1)-P^-1(i)| equals 1 or 2 for i=1,2,...,n-1.at n=25A038718
• a(n) is the smallest k such that (k^3 + 1)/(n^3 + 1) is an integer > 1.at n=33A065964
• Number of polyhexes with n cells that tile the plane by translation or by 180-degree rotation (Conway criterion).at n=10A075212
• Triangle T(n,d) (listed row-wise: T(1,1)=1, T(2,1)=1, T(2,2)=1, T(3,1)=2, T(3,2)=2, T(3,3)=1, ...) giving the number of n-edge general plane trees with root degree d that are fixed by the two-fold application of Catalan Automorphisms A057511/A057512 (Deep rotation of general parenthesizations/plane trees).at n=78A079218
• Number of Catalan objects fixed by two-fold application of the Catalan bijections A057511/A057512 (Deep rotation of general parenthesizations/plane trees).at n=12A079223
• Sum of largest parts (counted with multiplicity) in all compositions of n.at n=12A097976
• Number of 3-step one or two space at a time bishop's tours on an n X n board summed over all starting positions.at n=21A187047
• Numbers whose digits are a permutation of [0,...,n] and which contain the product of any two adjacent digits as a substring.at n=20A203569
• In base 5, numbers n which have 5 distinct digits, do not start with 0, and have property that the product (written in base 5) of any two adjacent digits is a substring of n.at n=4A210016
• Numbers n such that gcd(n, phi(n)) = gcd(phi(n), sigma(n)) = gcd(sigma(n), n) = tau(n).at n=37A217301
• a(n) is the smallest b > 1 such that p = prime(n) satisfies b^(p-1) == 1 (mod p^3).at n=30A249275
• Number of (n+2)X(1+2) 0..1 arrays with every 3X3 subblock diagonal maximum plus antidiagonal maximum nondecreasing horizontally and vertically.at n=2A253978
• Number of (n+2) X (3+2) 0..1 arrays with every 3X3 subblock diagonal maximum plus antidiagonal maximum nondecreasing horizontally and vertically.at n=0A253980
• T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with every 3X3 subblock diagonal maximum plus antidiagonal maximum nondecreasing horizontally and vertically.at n=3A253985
• T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with every 3X3 subblock diagonal maximum plus antidiagonal maximum nondecreasing horizontally and vertically.at n=5A253985
• Number of (n+2)X(3+2) 0..1 arrays with every 3X3 subblock diagonal maximum plus antidiagonal maximum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=0A254385
• T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with every 3X3 subblock diagonal maximum plus antidiagonal maximum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=3A254390
• T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with every 3X3 subblock diagonal maximum plus antidiagonal maximum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=5A254390