login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A061495 a(n) = lcm(3n+1, 3n+2, 3n+3). 1
6, 60, 504, 660, 2730, 2448, 7980, 6072, 17550, 12180, 32736, 21420, 54834, 34440, 85140, 51888, 124950, 74412, 175560, 102660, 238266, 137280, 314364, 178920, 405150, 228228, 511920, 285852, 635970, 352440, 778596, 428640, 941094, 515100 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Harry J. Smith, Table of n, a(n) for n = 0..1000

FORMULA

If n is odd, then all three factors are mutually coprime, so lcm = (3n+1)(3n+2)(3n+3), else one half that expression. - Christopher Carl Heckman, Sep 29 2004

Empirical g.f.: 6*(10*x^6+28*x^5+125*x^4+70*x^3+80*x^2+10*x+1) / ((x-1)^4*(x+1)^4). - Colin Barker, Feb 25 2013

EXAMPLE

a(0) = lcm(1,2,3) = 6; a(1) = lcm(4,5,6) = 60; etc.

PROG

(PARI) A061495(n)=lcm(3*n+1, lcm(3*n+2, 3*n+3))

(PARI) { for (n=0, 1000, write("b061495.txt", n, " ", lcm(3*n+1, lcm(3*n+2, 3*n+3))) ) } \\ Harry J. Smith, Jul 23 2009

CROSSREFS

Sequence in context: A269760 A043033 A179711 * A220411 A248217 A102232

Adjacent sequences:  A061492 A061493 A061494 * A061496 A061497 A061498

KEYWORD

easy,nonn

AUTHOR

Jason Earls, Jun 12 2001

EXTENSIONS

More terms from several contributors.

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 19 23:24 EDT 2020. Contains 337198 sequences. (Running on oeis4.)