A037290 Number of self-converse rings (isomorphic to inverse) with n elements.

1, 2, 2, 9, 2, 4, 2, 40, 9, 4, 2, 18, 2, 4, 4, 242, 2, 18, 2, 18, 4, 4, 2, 80, 9, 4, 47, 18, 2, 8, 2

Offset: 1

Author

Christian G. Bower, Jun 15 1998

Keywords

• nonn
• hard
• mult
• nice

Links

• A. V. Lelechenko, Parity of the number of primes in a given interval and algorithms of the sublinear summation, arXiv:1305.1639 [math.NT], 2013.
• Christof Noebauer, Home page

Crossrefs

Cf. A027623, A037289.

Extensions

a(16) and a(27) from Christof Noebauer (christof.noebauer(AT)algebra.uni-linz.ac.at), Oct 17 2000