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

1,1

Comments

a(21) > 10^12.

Links

Table of n, a(n) for n=1..20.

Example

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).

Sequence in context: A283035 A284764 A271421 * A387439 A064204 A054644

Adjacent sequences: A378925 A378926 A378927 * A378929 A378930 A378931

Keyword

nonn,more

Author

Toshitaka Suzuki, Dec 11 2024

Status

approved