20561

Appears in sequences

• Sums of 5 distinct powers of 4.at n=38A038473
• Number of the essentially different permutations of the numbers 0 to n such that the sum of adjacent numbers is a square.at n=34A108658
• Sums of p-th to the q-th prime where p and q are twin primes.at n=34A114379
• a(n) = 1 - 2*n^2 + 4*n*(1 + 2*n^2)/3.at n=20A168547
• a(n) = (4*n^3 - 6*n^2 + 8*n + 9 + 3*(-1)^n)/12.at n=40A168582
• Expansion of psi(x^2) * phi(x^7) / (f(-x) * f(-x^7)) in powers of x where phi(), psi(), f() are Ramanujan theta functions.at n=30A193826
• Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 297", based on the 5-celled von Neumann neighborhood.at n=28A280614