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!)
A062027 a(1) = a(2) = a(3) = 1; and for n>3 a(n) = 1*2*3*4 + 2*3*4*5 + 3*4*5*6 + ... + (n-1)*n*1*2 + n*1*2*3, the sum of the cyclic product of terms taken four at a time, final term being n*1*2*3 = 6n. 2
1, 1, 1, 96, 274, 720, 1680, 3520, 6750, 12048, 20284, 32544, 50154, 74704, 108072, 152448, 210358, 284688, 378708, 496096, 640962, 817872, 1031872, 1288512, 1593870, 1954576, 2377836, 2871456, 3443866, 4104144, 4862040, 5728000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,1000

FORMULA

a(n) = (n+1)(n)(n-1)(n-2)(n-3)/5 + n(n^2 -n +6).

EXAMPLE

a(5) = 1*2*3*4 + 2*3*4*5 + 3*4*5*1 + 4*5*1*2 + 5*1*2*3 = 274.

PROG

(PARI) { a=1; for (n=1, 1000, if (n>3, a=(n + 1)*n*(n - 1)*(n - 2)*(n - 3)/5 + n*(n^2 - n + 6)); write("b062027.txt", n, " ", a) ) } \\ Harry J. Smith, Jul 30 2009

CROSSREFS

Sequence in context: A232939 A202591 A202584 * A320883 A048189 A304830

Adjacent sequences:  A062024 A062025 A062026 * A062028 A062029 A062030

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Jun 02 2001

EXTENSIONS

More terms from Jason Earls, Jun 07 2001

Term a(4) corrected by Harry J. Smith, Jul 30 2009

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 February 28 11:08 EST 2020. Contains 332323 sequences. (Running on oeis4.)