|
Search: id:A095661
|
|
| |
|
| 3, 13, 35, 75, 140, 238, 378, 570, 825, 1155, 1573, 2093, 2730, 3500, 4420, 5508, 6783, 8265, 9975, 11935, 14168, 16698, 19550, 22750, 26325, 30303, 34713, 39585, 44950, 50840, 57288, 64328, 71995, 80325, 89355, 99123, 109668, 121030, 133250, 146370
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
COMMENT
|
If Y is a 3-subset of an n-set X then, for n>=6, a(n-6) is the number of 4-subsets of X having at most one element in common with Y. - Milan R. Janjic (agnus(AT)blic.net), Nov 23 2007
|
|
FORMULA
|
G.f.: (3-2*x)/(1-x)^5.
a(n)= (n+12)*binomial(n+3, 3)/4 = 3*b(n)-2*b(n-1), with b(n):=binomial(n+4, 4); cf. A000332.
|
|
CROSSREFS
|
Sequence in context: A026084 A016061 A137976 this_sequence A058214 A108480 A061483
Adjacent sequences: A095658 A095659 A095660 this_sequence A095662 A095663 A095664
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
Wolfdieter Lang (wolfdieter.lang_AT_physik_DOT_uni-karlsruhe_DOT_de), Jun 11 2004
|
|
|
Search completed in 0.002 seconds
|
