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%I #16 Jan 01 2024 18:15:21
%S 2,3,4,5,7,9,13,25
%N 1 plus the n-th divisor of 24.
%C 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.
%D J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, 3rd. ed., 1993. Table 16.1, p. 407.
%H Ken Ono, Larry Rolen, Sarah Trebat-Leder, <a href="http://arxiv.org/abs/1403.3712">Classical and umbral Moonshine: connections and p-adic properties</a>, arXiv:1403.7312v1 [math.NT]
%F a(n) = 1 + A018253(n).
%t 1 + Divisors[24] (* _Wesley Ivan Hurt_, Jan 01 2024 *)
%Y Cf. A000521, A007240, A018253, A018623.
%Y A subsequence of A238839.
%K nonn,easy,fini,full
%O 1,1
%A _Omar E. Pol_, Mar 18 2014
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