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A136724
Numbers divisible by 4 that are not powers of 2.
2
12, 20, 24, 28, 36, 40, 44, 48, 52, 56, 60, 68, 72, 76, 80, 84, 88, 92, 96, 100, 104, 108, 112, 116, 120, 124, 132, 136, 140, 144, 148, 152, 156, 160, 164, 168, 172, 176, 180, 184, 188, 192, 196, 200, 204, 208, 212, 216, 220, 224, 228, 232, 236, 240, 244, 248
OFFSET
1,1
COMMENTS
Primitive dimensions of Hadamard matrices which cannot be obtained as tensor powers of the primitive matrix 2 X 2 {{1,1},{1,-1}}.
5+7=12=2+4+6, 9+11=20=2+4+6+8,.. Numbers that can be expressed as sum of two or more positive consecutive odd numbers AND as sums of two or more positive consecutive even numbers. - Vladimir Joseph Stephan Orlovsky, May 11 2010
Numbers in A008586 but not in A000079. - Michel Marcus, Nov 07 2013
Nicomachus called these numbers "odd-times even". - Eric M. Schmidt, Mar 30 2019
LINKS
MATHEMATICA
a = {}; Do[k = 4n; If[Round[Log[k]/Log[2]] == Log[k]/Log[2], [null], AppendTo[a, k]], {n, 1, 100}]; a
CROSSREFS
Cf. A007299.
Sequence in context: A206552 A332832 A065201 * A361868 A316597 A329142
KEYWORD
nonn
AUTHOR
Artur Jasinski, Jan 19 2008
STATUS
approved