211200

Appears in sequences

• Successive positions in Tower of Hanoi (with three pegs {0,1,2}) where xyz means smallest disk is on peg z, second smallest is on peg y, third smallest on peg x, etc. and leading zeros indicate largest disks are all on peg 0.at n=36A055662
• Triangle T(n,k) of ways n couples can sit in a row with exactly k of them together.at n=18A193639
• Sequence A255412 sorted into ascending order, with duplicates removed.at n=13A254035
• a(n) = A000203(A255334(n)).at n=13A255412
• Consider numbers n = concat(x,y,z) such that the product x*y*z | n. Leading zeros in y and z allowed. Sequence lists numbers that admit different concatenations.at n=28A256518
• Expansion of x^4*(5 - 16*x + 13*x^2)/(1 - 2*x)^4.at n=14A268587
• Real parts of the recursive sequence a(n+2) = Sum_{k=0..n} binomial(n,k)*a(k)*a(n+1-k), with a(0)=2, a(1)=2i.at n=9A289088
• Numbers m such that the smallest digit in the decimal expansion of 1/m is 3, ignoring leading and trailing 0's.at n=39A352157
• G.f.: Sum_{k>=0} x^(k^2) * Product_{j=1..k} ((1 + x^j)/(1 - x^j))^2.at n=33A376854
• Triangle read by rows, with T(n,k) giving the number of n X n Boolean matrices with exactly k ones having at least one zero row and at least one zero column.at n=41A392483