1,2

A permutation of the natural numbers.

Amiram Eldar, Table of n, a(n) for n = 1..10000

a(n)=A181819(A025487(n)).

a(n)=A122111(A181815(n)).

A025487(8) = 24 = 2^3*3 has the exponents (3,1) in its canonical prime factorization. Accordingly, a(8) = prime(3)*prime(1) (i.e., A000040(3)*A000040(1)), which equals 5*2=10.

A181815 is another mapping from the members of A025487 to the positive integers. Also see A181819, A181821.

Sequence in context: A084690 A194963 A072794 * A199426 A119257 A266645

Adjacent sequences: A181817 A181818 A181819 * A181821 A181822 A181823

nonn

Matthew Vandermast, Dec 07 2010

approved