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Search: a106374 -id:a106374
Displaying 1-4 of 4 results found. page 1
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A005776 Exponents m_i associated with Weyl group W(E_8). +10
15
1, 7, 11, 13, 17, 19, 23, 29 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Numbers coprime to 30 in that number's reduced residue system. - Alonso del Arte, Oct 03 2017
REFERENCES
H. S. M. Coxeter and W. O. J. Moser, Generators and Relations for Discrete Groups, 4th ed., Springer-Verlag, NY, reprinted 1984, p. 141.
LINKS
Abel Jansma, E_8 Symmetry Structures in the Ising model, Master's thesis, University of Amsterdam, 2018.
MATHEMATICA
Select[Range[30], GCD[30, #] == 1 &] (* Alonso del Arte, Oct 03 2017 *)
PROG
(Magma) Exponents(RootDatum("E8")); // Sergei Haller (sergei(AT)sergei-haller.de), Dec 21 2006
(PARI) select(n->gcd(n, 30)==1, [1..29]) \\ Charles R Greathouse IV, Oct 17 2017
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
STATUS
approved
A106403 Primitive exponents of the Weyl group W(E_8). +10
5
3, 15, 23, 27, 35, 39, 47, 59 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
REFERENCES
C. Chevalley, The Betti numbers of the exceptional Lie groups, pp. 21-24 of Proc. Internat Congress Math., Cambridge 1950, Amer. Math. Soc., 1952.
LINKS
FORMULA
Equals 2*A005776(n) + 1.
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
N. J. A. Sloane, May 30 2005
STATUS
approved
A106373 Primitive exponents of the Weyl group W(E_6). +10
4
3, 9, 11, 15, 17, 23 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
REFERENCES
C. Chevalley, The Betti numbers of the exceptional Lie groups, pp. 21-24 of Proc. Internat Congress Math., Cambridge 1950, Amer. Math. Soc., 1952.
LINKS
FORMULA
Equals 2*A005556(n) + 1.
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
N. J. A. Sloane, May 30 2005
STATUS
approved
A109161 Triangle read by rows: T(n, k) = n*(n+9) + k + 5, with T(0, 0) = 5 and T(1, 0) = 15. +10
3
5, 15, 16, 27, 28, 29, 41, 42, 43, 44, 57, 58, 59, 60, 61, 75, 76, 77, 78, 79, 80, 95, 96, 97, 98, 99, 100, 101, 117, 118, 119, 120, 121, 122, 123, 124, 141, 142, 143, 144, 145, 146, 147, 148, 149, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
S. Helgason, A Centennial: Wilhelm Killing and the Exceptional Groups, Mathematical Intelligencer 12, no. 3 (1990). [See p. 3.]
FORMULA
T(n, k) = n*(n+9) + k + 5, with T(0, 0) = 5 and T(1, 0) = 15.
EXAMPLE
Triangle begins as:
5;
15, 16;
27, 28, 29;
41, 42, 43, 44;
57, 58, 59, 60, 61;
75, 76, 77, 78, 79, 80;
MATHEMATICA
T[n_, k_]:= If[n==0 && k==0, 5, If[k==0 && n==1, 15, n*(n+9) +k +5]];
Table[T[n, k], {n, 0, 12}, {k, 0, n}]//Flatten
PROG
(Sage)
@CachedFunction
def T(n, k):
if (n==0 and k==0): return 5
elif (k==0 and n==1): return 15
else: return n*(n + 9) + k + 5
flatten([[T(n, k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Feb 05 2021
CROSSREFS
KEYWORD
nonn,tabl,easy,less
AUTHOR
Roger L. Bagula, May 06 2007
EXTENSIONS
More terms and edits by G. C. Greubel, Feb 05 2021
STATUS
approved
page 1

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Last modified August 30 00:57 EDT 2024. Contains 375520 sequences. (Running on oeis4.)