A005018 Divisors of 20: a finite sequence associated with the Lie algebra A_4.

1, 2, 4, 5, 10, 20

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• fini
• full
• easy

References

• E. B. Dynkin, Semisimple subalgebras of semisimple Lie algebras, Am. Math. Soc. Translations, Series 2, Vol. 6, 1957, pp. 111-244, esp. p. 211.

Links

• Index entries for sequences related to divisors of numbers

Programs

PARI

divisors(20)

Sage

divisors(20); # Zerinvary Lajos, Jun 13 2009

Formula

a(n) = A161706(n-1). - Reinhard Zumkeller, Jun 21 2009