A374600 If n = i^2 * A005117(j) for some i, j > 0 then a(n) = j^2 * A005117(i).

1, 4, 9, 2, 16, 25, 36, 8, 3, 49, 64, 18, 81, 100, 121, 5, 144, 12, 169, 32, 196, 225, 256, 50, 6, 289, 27, 72, 324, 361, 400, 20, 441, 484, 529, 7, 576, 625, 676, 98, 729, 784, 841, 128, 48, 900, 961, 45, 10, 24, 1024, 162, 1089, 75, 1156, 200, 1225, 1296

Offset: 1

Author

Rémy Sigrist, Jul 13 2024

Keywords

• nonn

Comments

This sequence is a self-inverse permutation of the positive integers with infinitely many fixed points.

Examples

			For n = 84: 84 = 2^2 * A005117(14), so a(84) = 14^2 * A005117(2) = 392.
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10000
• Rémy Sigrist, PARI program
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

See A374611 for a similar sequence.

Cf. A000188, A005117, A007913, A249327.

Programs

PARI

\\ See Links section.

Formula

a(A249327(n, k)) = A249327(k, n).

a(n) = n iff n = k^2 * A005117(k) for some k > 0.