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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
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
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;
MATHEMATICA
Module[{nn=10, c}, c=Range[nn]^3; Flatten[Table[Take[c, n], {n, 10}]]] (* Harvey P. Dale, Mar 05 2014 *)
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
Sequence in context: A198988 A098367 A141228 * A258718 A019864 A230151
KEYWORD
easy,nonn,tabl
AUTHOR
Peter Bala, Sep 25 2007
EXTENSIONS
Offset changed by Reinhard Zumkeller, Nov 11 2012
STATUS
approved