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Small equivalence classes (A227722) of subgroups of nimber addition (A190939).
3

%I #18 Aug 09 2013 14:17:09

%S 1,3,5,6,15,17,18,51,20,85,105,24,102,90,60,255,257,258,771,260,1285,

%T 1545,264,1542,1290,780,3855,272,4369,4641,5185,6273,288,4626,4386,

%U 6210,5250,816,13107,15555,320,5140,6180,4420,4740,1360,21845

%N Small equivalence classes (A227722) of subgroups of nimber addition (A190939).

%C Each entry of this sequence represents the same small equivalence class (sec) of Boolean functions as the corresponding entry of A190939. While A190939 represents each sec by the unique odd number among the numeric values of its functions, this sequence represents each sec by the smallest among these numbers (as an entry of A227722).

%C All big equivalence classes (bec) of Boolean functions are also small equivalence classes. So all entries in the sequence of sona-becs (A227960) are also in this sequence of sona-secs.

%C This sequence takes its order from A190939, so it is not monotonic. Thus it is not a subsequence of A227722, and does not contain A227960 as a subsequence.

%C First entries: 1, 3, 5, 6, 15, 17, 18, 51, 20, 85, 105, 24, 102, 90, 60, 255.

%C First entries in numerical order: 1, 3, 5, 6, 15, 17, 18, 20, 24, 51, 60, 85, 90, 102, 105, 255.

%H Tilman Piesk, <a href="/A227963/b227963.txt">Table of n, a(n) for n = 0..2824</a>

%H Tilman Piesk, <a href="/A227963/a227963_1.txt">Table of n, A190939(n), a(n) for n = 0..2824</a> and <a href="http://commons.wikimedia.org/wiki/File:Z2%5E4;_subgroups_list.svg#File">the same with a graphical explanation for n = 0..66</a>

%H Tilman Piesk, <a href="http://en.wikiversity.org/wiki/Subgroups_of_nimber_addition">Subgroups of nimber addition</a> (Wikiversity)

%H Tilman Piesk, <a href="http://en.wikiversity.org/wiki/Equivalence_classes_of_Boolean_functions#sec">Small equivalence classes of Boolean functions</a>

%e A190939(3) = 9. 9 belongs to the sec A227722(4) = 6. So a(3) = 6.

%e A190939(8) = 65. 65 belongs to the sec A227722(10) = 20. So a(8) = 20.

%K nonn

%O 0,2

%A _Tilman Piesk_, Aug 08 2013