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Number of Abelian groups of order 4n+1.
1

%I #11 Sep 23 2023 07:29:11

%S 1,1,2,1,1,1,2,1,1,1,1,2,2,1,1,1,1,1,1,1,5,1,1,1,1,1,1,1,1,2,2,3,1,1,

%T 1,1,1,1,2,1,1,1,2,1,1,1,1,3,1,1,1,1,1,1,1,1,4,1,1,1,1,2,1,1,1,2,1,1,

%U 1,1,1,1,2,1,3,1,1,1,1,1,1,2,1,2,1,1,1,1,1,1,2,1,2,1,1,1,1,1,1,1,1,5,1,1,1

%N Number of Abelian groups of order 4n+1.

%t a[n_] := FiniteAbelianGroupCount[4*n + 1]; Array[a, 100, 0] (* _Amiram Eldar_, Sep 23 2023 *)

%Y Bisection of A101871.

%Y Cf. A101874, A101876.

%K nonn,easy

%O 0,3

%A _N. J. A. Sloane_, Jan 28 2005

%E More terms from _Joshua Zucker_, May 10 2006