|
| |
|
|
A007042
|
|
Diagonal of partition triangle A047812.
(Formerly M2451)
|
|
4
| |
|
|
0, 1, 3, 5, 9, 13, 20, 28, 40, 54, 75, 99, 133, 174, 229, 295, 383, 488, 625, 790, 1000, 1253, 1573, 1956, 2434, 3008, 3716, 4563, 5602, 6840, 8347, 10141, 12308, 14881, 17975, 21635, 26013, 31183, 37336, 44581, 53172, 63259, 75173, 89132, 105556
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,3
|
|
|
COMMENTS
| For n>2: Also number of partitions of n into parts <= n-2: a(n)=A026820(n+1,n-1). [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jan 21 2010]
|
|
|
REFERENCES
| R. K. Guy, Parker's permutation problem involves the Catalan numbers, Amer. Math. Monthly 100 (1993), 287-289.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
|
|
|
FORMULA
| a(n) = A000041(n+1)-2, i.e. a(n) = -2 + number of partitions of n+1. - Vladeta Jovovic (vladeta(AT)eunet.rs), Oct 06 2001
|
|
|
CROSSREFS
| Sequence in context: A108754 A033499 A106607 * A178415 A076274 A058989
Adjacent sequences: A007039 A007040 A007041 * A007043 A007044 A007045
|
|
|
KEYWORD
| nonn,easy,nice
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), R. K. Guy
|
|
|
EXTENSIONS
| More terms from James A. Sellers (sellersj(AT)math.psu.edu)
|
| |
|
|
