OFFSET
0,2
COMMENTS
The 146th prime number (839) and some of its multiples are related to the exceptional Lie group E_8 calculation because the result is a matrix with 453060 rows and columns. The size of the matrix is the member a(540)=453060 of this sequence. The number 839 is the largest prime factor of 453060 because we can write 2*2*3*3*3*5*839=453060. The number of entries of the matrix is the member a(244652400)=453060*453060=205263363600.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
American Institute of Mathematics, Mathematicians Maps E_8.
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
From G. C. Greubel, Oct 25 2016: (Start)
a(n) = 2*a(n-1) - a(n-2).
G.f.: (839*x)/(1 - x)^2.
E.g.f.: 839*x*exp(x). (End)
EXAMPLE
a(1)=839. a(540)=540*839=453060. a(244652400)=244652400*839=205263363600.
MATHEMATICA
839Range[0, 40] (* Harvey P. Dale, Sep 13 2011 *)
LinearRecurrence[{2, -1}, {0, 839}, 25] (* G. C. Greubel, Oct 25 2016 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, Nov 27 2007
STATUS
approved