login
A239048
1 plus the n-th divisor of 24.
1
2, 3, 4, 5, 7, 9, 13, 25
OFFSET
1,1
COMMENTS
Also Coxeter number (denoted m(X)) of the Niemeier lattices X whose root systems are of pure A-type according to the ADE classification; see Ono-Rolen-Trebat paper, page 3, Table 1, Pure A-type root systems.
REFERENCES
J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, 3rd. ed., 1993. Table 16.1, p. 407.
LINKS
Ken Ono, Larry Rolen, Sarah Trebat-Leder, Classical and umbral Moonshine: connections and p-adic properties, arXiv:1403.7312v1 [math.NT]
FORMULA
a(n) = 1 + A018253(n).
MATHEMATICA
1 + Divisors[24] (* Wesley Ivan Hurt, Jan 01 2024 *)
CROSSREFS
A subsequence of A238839.
Sequence in context: A236166 A017834 A286225 * A219898 A263360 A050763
KEYWORD
nonn,easy,fini,full
AUTHOR
Omar E. Pol, Mar 18 2014
STATUS
approved