A353946 a(n) = (pi(2n-1) - pi(n-1))^pi(n) for n > 1, a(1) = 0.

0, 2, 4, 4, 8, 8, 81, 16, 81, 256, 1024, 1024, 4096, 729, 4096, 15625, 78125, 16384, 390625, 65536, 390625, 1679616, 10077696, 10077696, 10077696, 10077696, 40353607, 40353607, 282475249, 282475249, 8589934592, 1977326743, 1977326743, 8589934592, 8589934592, 31381059609, 1000000000000

Offset

1,2

Comments

Number of functions from P to Q, where P is the set of primes <= n and Q is the set of primes q such that n <= q <= 2n-1.

Links

Table of n, a(n) for n=1..37.

Formula

a(n) = A035250(n)^A000720(n) for n > 1, a(1) = 0.

Mathematica

Join[{0}, Table[(PrimePi[2 n - 1] - PrimePi[n - 1])^PrimePi[n], {n, 2, 30}]]

Crossrefs

Cf. A000720 (pi), A035250, A352749.

Sequence in context: A048656 A107848 A285273 * A188824 A181212 A233394

Adjacent sequences: A353943 A353944 A353945 * A353947 A353948 A353949

Keyword

nonn

Author

Wesley Ivan Hurt, May 12 2022

Status

approved