# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/

Search: id:a001066
Showing 1-1 of 1

%I A001066 #17 Nov 21 2013 13:11:11
%S A001066 3,6,8,10,14,15,16,20,21,24,28,30,35,36,42,45,48,52,55,56,63,66,70,72,
%T A001066 78,80,90,91,96,99,104,105,110,120,126,132,133,136,143,153,156,160,
%U A001066 168,171,182,190,195,198,210,224,231,240,248,253,255,266,272,276,286,288,300,306
%N A001066 Dimensions (sorted, with duplicates removed) of real simple Lie algebras.
%C A001066 The possible dimensions of real simple Lie algebras are the numbers n and 2n where n runs through the dimensions of the complex simple Lie algebras.
%D A001066 Freeman J. Dyson, Missed opportunities, Bull. Amer. Math. Soc. 78 (1972), 635-652.
%D A001066 N. Jacobson, Lie Algebras. Wiley, NY, 1962; see pp. 141-146.
%H A001066 Reinhard Zumkeller, <a href="/A001066/b001066.txt">Table of n, a(n) for n = 1..10000</a>
%F A001066 Numbers n and 2n as n runs through A003038.
%e A001066 6 is the dimension of the real simple Lie algebra SL_2(C).
%t A001066 max = 18; sa = Table[k*(k+2), {k, 1, max}]; sb = Table[k*(2k+1), {k, 2, max}]; sd := Table[k*(2k-1), {k, 4, max}]; se = {14, 52, 78, 133, 248}; Select[ Union[sa, 2*sa, sb, 2*sb, sd, 2*sd, se, 2*se], # <= max^2 &] (* _Jean-François Alcover_, Apr 02 2012, after A003038 *)
%o A001066 (Haskell)
%o A001066 import Data.Set (deleteFindMin, fromList, insert)
%o A001066 a001066 n = a001066_list !! (n-1)
%o A001066 a001066_list = f (fromList [h, 2 * h]) $ tail a003038_list where
%o A001066    h = head a003038_list
%o A001066    f s (x:xs) = m : f (x `insert` (( 2 * x) `insert` s')) xs where
%o A001066      (m, s') = deleteFindMin s
%o A001066 -- _Reinhard Zumkeller_, Dec 16 2012
%Y A001066 Cf. A003038.
%Y A001066 Subsequences, apart from some initial terms: A000217, A000384, A002378, A005563, A014105.
%K A001066 nonn,nice,easy
%O A001066 1,1
%A A001066 Richard E. Borcherds (reb(AT)math.berkeley.edu)
%E A001066 Entry revised by _N. J. A. Sloane_, Mar 16 2007

# Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE