A236432 a(n) = (2*n-1)*210; numbers which are 210 times an odd number.

210, 630, 1050, 1470, 1890, 2310, 2730, 3150, 3570, 3990, 4410, 4830, 5250, 5670, 6090, 6510, 6930, 7350, 7770, 8190, 8610, 9030, 9450, 9870, 10290, 10710, 11130, 11550, 11970, 12390, 12810, 13230, 13650, 14070, 14490, 14910, 15330, 15750, 16170, 16590, 17010

Offset

1,1

Comments

This is a subsequence of A235921, from which it differs for the first time at n = 1062348, where a(n) = ((2*1062348)-1)*210 = 446185950, while A235921(n) = 446185740.

Links

Antti Karttunen, Table of n, a(n) for n = 1..10001

Index entries for sequences which agree for a long time but are different.

Index entries for linear recurrences with constant coefficients, signature (2,-1).

Formula

a(n) = (2*n-1)*210 = 420*n - 210.

For all n, A236454(a(n)) = 8, while A053669(a(n)) >= 11. [Cf. comments at A235921]

From Elmo R. Oliveira, Dec 02 2025: (Start)

G.f.: 210*x*(x+1)/(x-1)^2.

E.g.f.: 210*(1 + (2*x-1)*exp(x)).

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

a(n) = A169825(n) - 210. (End)

Maple

A236432:=n->420*n - 210; seq(A236432(n), n=1..50); # Wesley Ivan Hurt, Mar 13 2014

Mathematica

Table[420 n - 210, {n, 50}] (* Wesley Ivan Hurt, Mar 13 2014 *)
LinearRecurrence[{2, -1}, {210, 630}, 41] (* Ray Chandler, Jul 14 2015 *)
210*Range[1, 81, 2] (* Harvey P. Dale, Apr 13 2020 *)

Prog

(Scheme) ;; Two alternative versions.
(define (A236432 n) (* (+ n n -1) 210))
(define (A236432 n) (- (* 420 n) 210))

Crossrefs

Cf. A053669, A169825, A235921, A236454.

Sequence in context: A235304 A121479 A235921 * A118279 A163263 A009127

Adjacent sequences: A236429 A236430 A236431 * A236433 A236434 A236435

Keyword

nonn,easy

Author

Antti Karttunen, Jan 25 2014

Status

approved