|
| |
|
|
A133820
|
|
Triangle whose rows are sequences of increasing cubes: 1; 1,8; 1,8,27; ... .
|
|
3
|
|
|
|
1, 1, 8, 1, 8, 27, 1, 8, 27, 64, 1, 8, 27, 64, 125, 1, 8, 27, 64, 125, 216, 1, 8, 27, 64, 125, 216, 343, 1, 8, 27, 64, 125, 216, 343, 512, 1, 8, 27, 64, 125, 216, 343, 512, 729, 1, 8, 27, 64, 125, 216, 343, 512, 729, 1000
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,3
|
|
|
COMMENTS
|
Reading the triangle by rows produces the sequence 1,1,8,1,8,27,1,8,27,64,..., analogous to A002260.
|
|
|
LINKS
|
_Reinhard Zumkeller_, Rows n = 1..120 of triangle, flattened
|
|
|
FORMULA
|
O.g.f.: (1+4qx+q^2x^2)/((1-x)(1-qx)^4) = 1 + x(1 + 8q) + x^2(1 + 8q + 27q^2) + ... .
|
|
|
EXAMPLE
|
Triangle starts
1;
1, 8;
1, 8, 27;
1, 8, 27, 64;
1, 8, 27, 64, 125;
|
|
|
PROG
|
(Haskell)
a133820 n k = a133820_tabl !! (n-1) !! (k-1)
a133820_row n = a133820_tabl !! (n-1)
a133820_tabl = map (`take` (tail a000578_list)) [1..]
-- Reinhard Zumkeller, Nov 11 2012
|
|
|
CROSSREFS
|
Cf. A000537 (row sums), A002260, A019522, A133819, A133821, A133823.
Sequence in context: A198988 A098367 A141228 * A019864 A198674 A168321
Adjacent sequences: A133817 A133818 A133819 * A133821 A133822 A133823
|
|
|
KEYWORD
|
easy,nonn,tabl
|
|
|
AUTHOR
|
Peter Bala, Sep 25 2007
|
|
|
EXTENSIONS
|
Offset changed by Reinhard Zumkeller, Nov 11 2012
|
|
|
STATUS
|
approved
|
| |
|
|
