2692538

Appears in sequences

• Number of binary vectors of length n containing no singletons.at n=32A006355
• Dirichlet convolution of Fibonacci numbers with themselves.at n=30A034744
• Number of distinct permutations generated by shuffling n cards with "clump size" <= 2.at n=28A047992
• Expansion of 2*x*(1 - x)/(1 - 3*x + x^2).at n=16A052995
• Layer counting sequence for hyperbolic tessellation by cuspidal triangles of angles (Pi/3,Pi/3,0) (this is the classical modular tessellation).at n=29A054886
• a(0) = 1, then twice the Fibonacci sequence.at n=31A055389
• Row sums of array T in A055818; twice the odd-indexed Fibonacci numbers after initial term.at n=16A055819
• Number of ways to tile a 3 X 2n room with 1 X 2 Tatami mats. At most 3 Tatami mats may meet at a point.at n=29A068922
• Numbers with two representations as the sum of two Fibonacci numbers.at n=28A078642
• Number of meaningful differential operations of the n-th order on the space R^6.at n=27A090991
• a(n) = 2*F(n-1) = L(n) - F(n), where F(n) and L(n) are Fibonacci and Lucas numbers respectively.at n=32A118658
• Number of base 4 n-digit numbers with adjacent digits differing by one or less.at n=15A126358
• Expansion of g.f. x*(1+x+x^2)/(1-x-x^2).at n=30A128588
• Row sums of triangle A131779.at n=29A131780
• Expansion of x - x^2*(2*x+1)*(x^2-2) / ( (x^2-x-1)*(x^2+x-1) ).at n=30A133585
• Number of n X 2 binary arrays with all 1s connected, a path of 1s from top row to bottom row, and no 1 having more than two 1s adjacent.at n=28A163714
• Number of n X 2 binary arrays with all 1's connected, all corners 1, and no 1 having more than two 1's adjacent.at n=32A163733
• a(n) = 2*(A000045(n)-(n mod 2)) + 1 + (n mod 2).at n=31A166012
• Denominators of A178381(4*n+3)/A178381(4*n+2).at n=15A179133
• Number of sequences of n coin flips that win on the last flip, if the sequence of flips ends with (0,1,1) or (1,1,1).at n=32A198834