login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A008381 floor(n/5)*floor((n+1)/5)*floor((n+2)/5)*floor((n+3)/5). 0
0, 0, 0, 0, 0, 1, 1, 2, 4, 8, 16, 16, 24, 36, 54, 81, 81, 108, 144, 192, 256, 256, 320, 400, 500, 625, 625, 750, 900, 1080, 1296, 1296, 1512, 1764, 2058, 2401, 2401, 2744, 3136, 3584, 4096, 4096, 4608, 5184, 5832 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,8

LINKS

Table of n, a(n) for n=0..44.

FORMULA

a(n) = A002266(n)*A008496(n+1). a(n)= +a(n-1) +4*a(n-5) -4*a(n-6) -6*a(n-10) +6*a(n-11) +4*a(n-15) -4*a(n-16) -a(n-20) +a(n-21). G.f.: x^5*(x^10-2*x^9+4*x^8-4*x^7+8*x^6-8*x^5+8*x^4-4*x^3+4*x^2-2*x+1) * (1+x)^2 / ((x^4+x^3+x^2+x+1)^4 * (1-x)^5). [From R. J. Mathar, Apr 16 2010]

CROSSREFS

Sequence in context: A210025 A210023 A062116 * A083780 A101466 A129851

Adjacent sequences:  A008378 A008379 A008380 * A008382 A008383 A008384

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified May 25 03:00 EDT 2013. Contains 225634 sequences.