20655

Appears in sequences

• Number of 10's in all partitions of n.at n=45A024794
• a(n) = T(4n,n), where T is the array defined in A026082.at n=5A026091
• Odd numbers divisible by exactly 7 primes (counted with multiplicity).at n=18A046320
• a(n) = Product_{d|n, d^2<=n} (d+n/d); a(1)=1.at n=49A050214
• Numbers n such that the Diophantine equation x^4+y^5=n^4 has solutions.at n=32A070756
• Numbers k such that 2^k - prime(k) is prime.at n=19A078583
• Numbers k such that either 2^k + prime(k) or 2^k - prime(k) is prime.at n=43A130640
• Integers k such that 10^k + 63 is a prime number.at n=23A135115
• Matrix square of triangle W = A136231; also equals P^6, where P = triangle A136220.at n=32A136235
• Numbers x such that the sum of all their cyclic permutations is equal to that of all cyclic permutations of sigma(x) and all cyclic permutations of Euler totient function phi(x).at n=17A247317
• Odd numbers that are not of the form p + 2^a + 2^b with b > a > 0, and p prime.at n=6A268693
• a(n) is the number of n-digit positive integers with exactly two distinct base 10 digits.at n=8A335843
• a(0) = 1; a(n) = Sum_{k=0..n-1} binomial(n,k)^3 * a(k) * a(n-k-1).at n=4A346187