A341547 Number of rings with additive group (Z/nZ)^2.

1, 8, 8, 66, 8, 64, 8, 301, 175, 64, 8, 528, 8, 64, 64

Offset

1,2

Links

Table of n, a(n) for n=1..15.

B. Fine, Classification of Finite Rings of Order p^2, Mathematics Magazine, 66(4) (1993), 248-252.

C. R. Fletcher, Rings of Small Order, The Mathematical Gazette, 64(427) (1980), 9-22.

Christof Nöbauer, Numbers of rings on groups of prime power order

Christof Nöbauer, Home page

Mathematica

Clear[phi]; phi[1] = 1; phi[p_, 1] := 8; phi[2, 2] = 66;
phi[2, 3] = 301; phi[3, 2] = 175; phi[n_]:= Module[{aux = FactorInteger[n]}, Product[phi[aux[[i, 1]], aux[[i, 2]]], {i, Length[aux]}]];

Crossrefs

Cf. A341548, A341201, A341202, A037234, A037291, A127708, A127707, A037289, A037290, A038036, A307000, A339948, A000005.

Sequence in context: A215271 A202916 A165426 * A183395 A019216 A020552

Adjacent sequences: A341544 A341545 A341546 * A341548 A341549 A341550

Keyword

nonn,mult,more

Author

José María Grau Ribas, Feb 14 2021

Status

approved