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A262569
a(n) = (A002703(n)+2)/2.
3
1, 1, 1, 2, 4, 8, 13, 24, 45, 82, 151, 282, 529, 992, 1872, 3542, 6720, 12788, 24385, 46600, 89241, 171197, 328960, 633102, 1220160, 2354688, 4549753, 8801162, 17043506, 33038208, 64103989, 124491776, 241969989, 470681348, 916259632, 1784921474, 3479467177, 6787108713, 13247128045, 25870861824, 50552258560, 98832505868
OFFSET
3,4
COMMENTS
All of A002703, A262567, A262568 and this sequence are somewhat mysterious, so having four versions instead of one increases the chance that one of them will be found in a different context.
LINKS
Alexander Rosa and Štefan Znám, A combinatorial problem in the theory of congruences. (Russian), Mat.-Fys. Casopis Sloven. Akad. Vied 15 1965 49-59. [Annotated scanned copy]
FORMULA
a(n) = A262568(n)/2 = A262567(n) + 1.
MAPLE
See A262568.
CROSSREFS
Tables 1 and 2 of the first Rosa-Znám 1965 paper are A053632 and A178666 respectively.
Sequence in context: A000077 A054164 A226060 * A248876 A102704 A196720
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 20 2015
EXTENSIONS
More terms from R. J. Mathar, Oct 21 2015
STATUS
approved