A378928 Numbers k such that pi(k) = rad(k), where pi = A000720, rad = A007947.

4, 120, 350, 1116, 64700, 1304511, 3523884, 9559575, 189961956, 189964332, 514275185, 514275546, 1394194200, 3779851131, 75370121712, 204475052375, 204475052625, 204475053625, 204475054125, 204475054750

Offset: 1

Author

Toshitaka Suzuki, Dec 11 2024

Keywords

• nonn
• more

Comments

a(21) > 10^12.

Examples

			a(1) = 4 because the first solution of pi(x) = rad(x) is 4 since pi(4) = rad(4) = 2.
		

Crossrefs

Cf. A000720 (pi), A007947 (rad).