A005795
Degrees of fundamental invariants of Weyl group W(E_7).
Original entry on oeis.org
2, 6, 8, 10, 12, 14, 18
Offset: 1
- H. S. M. Coxeter and W. O. J. Moser, Generators and Relations for Discrete Groups, 4th ed., Springer-Verlag, NY, reprinted 1984, p. 141.
- G. J. Fox, Letter to N. J. A. Sloane, May 1991 [The notes on this letter reference this A-number but actually it contains a different sequence, which is not currently in the OEIS. - _Andrey Zabolotskiy_, Dec 09 2024]
A273867
Degrees of fundamental invariants of Weyl group W(E_6).
Original entry on oeis.org
2, 5, 6, 8, 9, 12
Offset: 1
A210576
Positive integers that cannot be expressed as sum of one or more nontrivial binomial coefficients.
Original entry on oeis.org
1, 2, 3, 4, 5, 7, 8, 9, 11, 13, 14, 17, 19, 23, 29
Offset: 1
The smallest terms in the sequence are 1, 2, 3, 4, 5, 7, 8, 9, 11, 13, 14 because 6, 10 and 15 cannot be terms, as these are the lowest nontrivial binomial coefficients; 12 and 16 cannot be terms, as these are the lowest sums of two nontrivial binomial coefficients; and sums of three or more nontrivial binomial coefficients cannot exclude any of the listed terms.
A210578 contains many of the integers that cannot be elements of this sequence.
Showing 1-3 of 3 results.
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