18291

Appears in sequences

• a(n) = floor(n(n+2)(2n+1)/8).at n=41A002717
• Expansion of 1/((1-x)(1-4x)(1-10x)).at n=4A016225
• Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 90.at n=29A031588
• Concatenations C1 and C2 and C3 are all prime (see the comment lines).at n=3A034818
• Concatenations C1 and C2 and C3 and C4 are all prime (see the comment lines).at n=8A034819
• Stirling-like number triangle defined by the sequence A000292=C(n+3,3).at n=23A080249
• Expansion of 1/(1 - x^2 - 2 x^3 + x^4).at n=32A122512
• a(n) = ceiling(n^3/3).at n=38A131477
• a(n) = (4*n^3 + 11*n^2 + 9*n + 2)/2.at n=20A135712
• Numbers that are repdigits with length > 2 in more than one base.at n=36A167783
• Second elementary symmetric function of the first n terms of (1,1,2,2,3,3,4,4,...).at n=25A203246
• Number of (w,x,y,z) with all terms in {1,...,n} and w+x<y+z.at n=14A212523
• Number of (w,x,y) with all terms in {0,...,n} and 2*w < |x+y-w|.at n=37A213396
• Number of primes of the form x^4 + 1 less than 10^n.at n=21A214452
• Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 278", based on the 5-celled von Neumann neighborhood.at n=15A280526
• Sum of all the parts in the partitions of n into 7 squarefree parts.at n=39A308953
• Numbers m such that beta(m) = tau(m)/2 + 1 where beta(m) is the number of Brazilian representations of m and tau(m) is the number of divisors of m.at n=34A326381
• Non-oblong composites m such that beta(m) = tau(m)/2 + 1 where beta(m) is the number of Brazilian representations of m and tau(m) is the number of divisors of m.at n=32A326388
• a(n) is the Wiener index of a tridon on n vertices.at n=43A349418
• Number of unlabeled strongly connected oriented graphs with n arcs.at n=11A350751