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A186297
a(n) = (A007520(n)-1)/2.
2
1, 5, 9, 21, 29, 33, 41, 53, 65, 69, 81, 89, 105, 113, 125, 141, 153, 165, 173, 189, 209, 221, 233, 245, 249, 261, 273, 281, 285, 293, 309, 321, 329, 341, 345, 369, 393, 405, 413, 429, 441, 453, 473, 485, 509, 525, 545, 561, 581, 585, 593
OFFSET
1,2
COMMENTS
a(n) = A055034(A007520(n)), n >= 1. This is the degree of the minimal polynomial C(A007520(n) ,x) of 2*cos(Pi/A007520(n)) (see A187360). a(n) is of course congruent 1 (mod 4). - Wolfdieter Lang, Oct 24 2013
FORMULA
a(n) = A186296(n)-1.
CROSSREFS
KEYWORD
nonn
AUTHOR
Marco Matosic, Feb 17 2011
STATUS
approved