A064505 Interchange primes and their squares.

1, 4, 9, 2, 25, 6, 49, 8, 3, 10, 121, 12, 169, 14, 15, 16, 289, 18, 361, 20, 21, 22, 529, 24, 5, 26, 27, 28, 841, 30, 961, 32, 33, 34, 35, 36, 1369, 38, 39, 40, 1681, 42, 1849, 44, 45, 46, 2209, 48, 7, 50, 51, 52, 2809, 54, 55, 56, 57, 58, 3481, 60, 3721, 62, 63, 64, 65, 66

Offset: 1

Author

Reinhard Zumkeller, Oct 16 2001

Keywords

• nonn

Comments

a(a(n)) = n, self-inverse permutation for the natural numbers.

Links

• Zak Seidov, Table of n, a(n) for n = 1..1000.
• Index entries for sequences that are permutations of the natural numbers

Programs

Mathematica

s=Range[1000]; Do[p=Prime[n];s[[p]]=p^2,{n,PrimePi[1000]}]; Do[p=Prime[n];s[[p^2]]=p,{n,PrimePi[Sqrt@1000]}];s (* Zak Seidov, Jun 29 2008 *)