20956

Appears in sequences

• a(n) = 10*n^3 - 6*n^2.at n=13A006592
• Expansion of 1/((1-x)*(1-x^2)^2*(1-x^3)^2*(1-x^4)^2*(1-x^5)*(1-x^6)).at n=30A045513
• Sum of squares of entries of Wilkinson's eigenvalue test matrix of order 2n+1.at n=31A059834
• a(n) = 4^n + 5^n + 7^n.at n=5A074562
• 47-gonal numbers.at n=30A095311
• Number of permutations of floor(i*9/7), i=0..n-1, with all sums of 3 adjacent terms unique.at n=7A152330
• Number of ways to place zero or more nonadjacent 1,0 1,1 2,0 2,2 3,0 3,3 4,1 4,3 polyhexes in any orientation on a planar nXnXn triangular grid.at n=8A155433
• a(n) is the smallest integer k such that the n-th (backward) difference of the partition sequence A000041 is positive from k onwards.at n=34A155861
• Number of length n sequences p(i=0..n-1) with 0<=p(i)<=i and having exactly 4 maxima.at n=8A181228
• T(n,k)=Number of length n sequences p(i=0..n-1) with 0<=p(i)<=i and having exactly k maxima.at n=74A181229
• a(n) = 2*n*(16*n - 13).at n=26A263228
• Number of compositions derived from the overpartitions of n.at n=11A297120
• Number of nX3 0..1 arrays with every element unequal to 2, 3 or 4 king-move adjacent elements, with upper left element zero.at n=11A303685
• Sum of the second largest parts of the partitions of n into 9 squarefree parts.at n=50A326531
• Expansion of e.g.f. exp(1 - exp(x)) * (exp(x) - 1)^2 / 2.at n=12A372624
• G.f. A(x) satisfies A(x)^2 = A(x^2) + 2*A(x^3).at n=32A377255
• a(n) is the length of chunks of the prime number sequence such that each chunk's sum of reciprocals is no less than 1/n, chunks being consecutive and of minimal length, for n>=2.at n=20A383891