78408

Appears in sequences

• a(n) = (1/3)*(n^2 + 2*n + 3)*(n+1)^2.at n=21A014820
• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 70.at n=7A031748
• Denominators of n divided by the product of the anti-divisors of n.at n=47A093396
• Non-perfect powers k for which q = A051903(k)/A051904(k) is an integer, A051904(k) > 1.at n=13A093770
• Unsigned member r=-8 of the family of Chebyshev sequences S_r(n) defined in A092184.at n=6A098308
• a(n) = A098916(n+2) + (1-n) * A067318(n).at n=6A121723
• Octagonal numbers of the form C*(3C - 2) with 3C - 2 = k^2 and C a composite number.at n=9A125511
• a(n) = 64*n^2 + 8.at n=34A158488
• Multiplicative order of 2 in Z/mZ with m=A104017(n).at n=34A165139
• G.f. satisfies: A(x) = 1 + x/(A(x) + x*A'(x)).at n=7A177384
• Numbers with prime factorization p^2*q^3*r^4 where p, q, and r are distinct primes.at n=11A190115
• Numbers n >= 0 such that n^2 + n*(n+1)/2 is a square.at n=3A220186
• G.f. A(x) satisfies: coefficient of x^n in A(x)^(2*n) equals A000172(n) = Sum_{k=0..n} C(n,k)^3, the n-th Franel number.at n=12A242903
• Positive octagonal numbers (A000567) that are squares (A000290) divided by 2.at n=1A259167
• Triangle T(n,t) read by rows: number of rooted forests with n 2-colored nodes and t rooted trees.at n=37A271878
• a(n) = n*(6*n^2 - 8*n + 3).at n=24A272378
• Numbers k such that (11*10^k - 113) / 3 is prime.at n=25A280557
• Number of ways to write n as an ordered sum of 6 squarefree numbers.at n=33A341066
• Square array T(n,k), n >= 1, k >= 1, read by antidiagonals, where T(n,k) = sqrt( Product_{a=1..n} Product_{b=1..k-1} (4*sin((2*a-1)*Pi/(2*n))^2 + 4*sin(2*b*Pi/k)^2) ).at n=41A341738
• Number of tilings of a 2 X n rectangle using 2 X 2 and 1 X 1 tiles, right trominoes and dominoes.at n=8A354131