44631

Appears in sequences

• Numerator of n*(n-2)*(2*n-1)/(2*(n-1)).at n=27A022997
• a(n) = Sum_{k=0..floor(n/2)} binomial(n-k,k-1)*3^(n-k-1).at n=10A099581
• a(n) = 3a(n-1) + 3a(n-2). a(0) = 1, a(1) = 4.at n=8A125145
• Triangle read by rows: T(n,k) is the number of sequences of length n on the alphabet {0,1,2,3}, containing k subsequences 00 (0<=k<=n-1).at n=29A128235
• Triangle read by rows, derived from an array of sequences generated from (1 + x)/ (1 - r*x - r*x^2).at n=63A180165
• Number of n X 8 binary matrices with no 2 X 2 block having four 1's.at n=1A181251
• T(n,k)=Number of nXk binary matrices with no 2X2 block having four 1's.at n=37A181253
• T(n,k)=Number of nXk binary matrices with no 2X2 block having four 1's.at n=43A181253
• T(n,k)=Number of nXk 0..3 arrays avoiding 11 horizontally, 22 vertically, 33 antidiagonally and 00 diagonally.at n=28A229412
• Numbers generated by recursive procedure a(n) = nozero(a(n-1) * 3), in which the function nozero(x) removes all zeros from x, starting with a(1) = 1.at n=28A243845
• Number of balanced ternary words of length n.at n=35A260938
• One half of numbers representable in at least two different ways as sums of four nonvanishing cubes. See A259060 for these numbers and their representations.at n=18A261241
• Numbers m such that both m^2-1 and m^2 are refactorable numbers (A033950) and that m^2 has more divisors than m^2-1.at n=21A342970
• G.f. A(x) satisfies A(x) = 1 + x*(1+x^3)*A(x)^3.at n=8A386496