A060309 A001067 appears to count the periodic points for a certain map. If so, then this is the sequence of the numbers of orbits of length n.

1, 0, 0, 0, 0, 115, 0, 452, 4874, 17461, 7062, 19696950, 50610, 242341439, 114877883680, 481832564850, 8919335150, 1461959530725195586, 8116326631140, 13054135924822447372, 72385602091336704890, 115013510658268698717, 1127506827209663824722

Offset: 1

Author

Thomas Ward, Apr 10 2001

Keywords

• nonn

Examples

			a(11) = 7062 because the 11th term of A001067 is 77683 and the first term is 1, so there should be (77683-1)/11 = 7062 orbits of length 11.
		

Links

• Y. Puri and T. Ward, Arithmetic and growth of periodic orbits, J. Integer Seqs., Vol. 4 (2001), #01.2.1.
• T. Ward, Exactly realizable sequences

Crossrefs

Cf. A001067, A060171, A060479.

Formula

If b(n) is the n-th term of A001067, then a(n)=(1/n)* |Sum_{d|n}mu(d)b(n/d)|, n<>2.

Extensions

a(18) corrected and more terms from Sean A. Irvine, Nov 08 2022