[seqfan] A181189

[Don Reble]

Seqfans:

> %I A181189
> %S 0,0,3,0,0,0,5,4,0,0,7,0,0,0,9,0,7,0,11,0,0,0
> %N Maximal number of elements needed to identify an abelian group
>    of order n by testing the order of random elements.

    The author says A181189(16) = 9; I think it's 13.
    Two of the size-16 groups have shapes [4,2,2] and [4,4],
    with element-orders:quantities
        [4,2,2] 1:1 2:7 4:8
        [4,4]   1:1 2:3 4:12
    The sample 1:1, 2:3, 4:8 (12 in total) won't distinguish those two.

    Do we agree?

    The other sequence values look good. Furthermore,
%S A181189 0,0,3,0,0,0,5,4,0,0,7,0,0,0,13,0,7,0,11,0,0,0,13,6,0,10,15,0,0,0,29,
%T A181189 0,0,0,19,0,0,0,21,0,0,0,23,16,0,0,37,8,11,0,27,0,19,0,29,0,0,0,31,0,
%U A181189 0,22,61,0,0,0,35,0,0,0,37,0,0,16,39,0,0,0,61,64,0,0,43,0,0,0,45,0,31

-- 
Don Reble  djr at nk.ca