A169825 Multiples of 420.

0, 420, 840, 1260, 1680, 2100, 2520, 2940, 3360, 3780, 4200, 4620, 5040, 5460, 5880, 6300, 6720, 7140, 7560, 7980, 8400, 8820, 9240, 9660, 10080, 10500, 10920, 11340, 11760, 12180, 12600, 13020, 13440, 13860, 14280, 14700, 15120, 15540, 15960, 16380, 16800

Offset: 0

Author

N. J. A. Sloane, May 30 2010

Keywords

• nonn
• easy

Comments

Numbers that are divisible by all of 1,2,3,4,5,6,7.

Links

• Erich Friedman, What's Special About This Number? (See the entry for "420")
• Index entries for linear recurrences with constant coefficients, signature (2,-1).

Crossrefs

Cf. A001477, A008589, A008596, A008597, A008602, A008603.

Cf. A135628, A169823, A169827, A249674.

Programs

Mathematica

Range[0, 100]*420 (* Paolo Xausa, Apr 17 2024 *)

PARI

a(n)=420*n \\ Charles R Greathouse IV, Apr 16 2024

Formula

a(n) = 420*n. - Wesley Ivan Hurt, Apr 11 2021

From Elmo R. Oliveira, Apr 16 2024: (Start)

G.f.: 420*x/(x-1)^2.

E.g.f.: 420*x*exp(x).

a(n) = 2*a(n-1) - a(n-2) for n >= 2.

a(n) = 7*A169823(n) = 14*A249674(n) = 15*A135628(n) = 20*A008603(n) = 21*A008602(n) = 28*A008597(n) = 30*A008596(n) = 60*A008589(n) = 420*A001477(n) = A169827(n)/2. (End)