|
Search: id:A068236
|
|
|
| A068236 |
|
First differences of (n+1)^5-n^5. |
|
+0
4
|
|
| 30, 180, 570, 1320, 2550, 4380, 6930, 10320, 14670, 20100, 26730, 34680, 44070, 55020, 67650, 82080, 98430, 116820, 137370, 160200, 185430, 213180, 243570, 276720, 312750, 351780, 393930, 439320, 488070, 540300, 596130, 655680
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
COMMENT
|
For n>=0, a(n) is equal to the number of functions f:{1,2,3,4,5}->{1,2,...,n+2} such that Im(f) contains 2 fixed elements. - Aleksandar M. Janjic and Milan R. Janjic (agnus(AT)blic.net), Feb 24 2007
|
|
LINKS
|
Milan Janjic, Enumerative Formulas for Some Functions on Finite Sets
|
|
FORMULA
|
a(n)=(n+2)^5-2*(n-1)^5+n^5
a(n)=30*A005900(n+1). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 02 2008]
|
|
CROSSREFS
|
Cf. A022521, A000584.
Sequence in context: A141221 A074357 A100430 this_sequence A101098 A054559 A042756
Adjacent sequences: A068233 A068234 A068235 this_sequence A068237 A068238 A068239
|
|
KEYWORD
|
nonn,new
|
|
AUTHOR
|
Eli McGowan (ejmcgowa(AT)mail.lakeheadu.ca), Mar 25 2002
|
|
|
Search completed in 0.002 seconds
|
