25978

Appears in sequences

• Number of positive integers <= 2^n of form x^2 + 3 y^2.at n=17A000205
• Numbers k such that sigma(phi(k)) = sigma(k) where sigma is the sum of divisors function A000203 and phi is the Euler totient function A000010.at n=9A033631
• Expansion of (1-3x)/(1-6x+8x^2+x^3).at n=8A114196
• Numbers n whose cubes are concatenations n^3 = x//y such that x is an anagram of y.at n=8A162946
• Numbers n such that sigma(sigma(phi(n))) = sigma(sigma(n)).at n=32A172466
• Cardinality of the set f^n({s}), where f is a variant of the Collatz function that replaces any element x in the argument set with both x/2 and 3*x+1, and s is an arbitrary irrational number.at n=15A208127
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 118", based on the 5-celled von Neumann neighborhood.at n=40A270187
• Numbers k such that (19*10^k + 101) / 3 is prime.at n=24A276672
• Number of non-self-conjugate partitions of n.at n=38A330644
• Numbers m such that sigma(m) = tau(m)! where sigma(k) = A000203(k) and tau(k) = A000005(k).at n=6A351866
• Expansion of Product_{i>=1, j>=0} (1 + x^(i * 5^j)).at n=58A373219