A027419 Number of distinct products i*j with 0 <= i, j <= n-th prime.

4, 7, 15, 26, 54, 73, 115, 143, 200, 297, 340, 461, 559, 619, 731, 904, 1098, 1178, 1393, 1556, 1652, 1912, 2103, 2391, 2785, 3008, 3150, 3392, 3535, 3789, 4647, 4941, 5363, 5555, 6299, 6495, 6963, 7481, 7864, 8403, 8968, 9196, 10115, 10364, 10805, 11068, 12271

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Crossrefs

Cf. A027384.

Programs

Maple

seq(A027384(ithprime(n)),n=1..40) ; # R. J. Mathar, Jun 09 2016

Python

from sympy import prime
def A027419(n): return len({i*j for i in range(1,prime(n)+1) for j in range(1,i+1)})+1 # Chai Wah Wu, Oct 13 2023

Extensions

More terms from Olivier Gérard, Nov 15 1997