24128

Appears in sequences

• Number of 3-dimensional polyominoes with n cells.at n=8A006766
• First row of spectral array W(sqrt(5)-1).at n=12A022165
• 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 77.at n=36A031575
• Triangle T(n,d) = number of distinct d-dimensional polyominoes (or polycubes) with n cells (0 < d < n).at n=30A049429
• Triangle read by rows: T(n,d) is the number of distinct properly d-dimensional polyominoes (or polycubes) with n cells (n >= 1, d >= 0).at n=39A049430
• a(0)=0, a(1)=1; for n>1, a(n) = 6*a(n-1)-4*a(n-2).at n=7A084326
• a(n) = (1+n)*(9 + 11*n + 4*n^2)/3.at n=25A172482
• Least number k such that n divides gcd(sigma(k), phi(k), tau(k)).at n=6A307640
• Least number k such that n divides gcd(sigma(k), phi(k), tau(k)).at n=13A307640
• Least number k such that n divides gcd(sigma(k), phi(k), tau(k)).at n=27A307640
• E.g.f. B(x) = 4 + Integral A(x)*C(x) dx such that C(x)^2 - B(x)^2 = 9 and B(x)^2 - A(x)^2 = 7.at n=4A323564
• Numbers m such that m = p^2 + k^2, with p > 0, where p = A007954(m) = the product of digits of m.at n=24A334557
• Triangular array read by rows: T(n,0) = 2^n, T(n,k) = Sum_{i=n-k..n, j=0..i-n+k, i<>n or j<>k} T(i,j) for k > 0.at n=34A337129
• Number of essentially parallel achiral series-parallel networks with n elements.at n=14A339158