A145684 Triangle T(n,k) = 2^(1 + floor((n-1)/2)) * A158893(n,k+1).

2, 16, 2, 60, 8, 4, 88, 12, 8, 4, 232, 32, 24, 16, 8, 288, 40, 32, 24, 16, 8, 688, 96, 80, 64, 48, 32, 16, 800, 112, 96, 80, 64, 48, 32, 16, 1824, 256, 224, 192, 160, 128, 96, 64, 32, 2048, 288, 256, 224, 192, 160, 128, 96, 64, 32

Offset

1,1

Comments

Row sums are 2, 18, 72, 112, 312, 408, 1024, 1248, 2976, 3488, ....

References

H. S. M. Coxeter, Regular Polytopes, 3rd ed., Dover, NY, 1973, pp. 159-162.

Links

Table of n, a(n) for n=1..55.

Example

The triangle starts in row n=1 with columns 0 <= k < n as:
     2;
    16,   2;
    60,   8,   4;
    88,  12,   8,   4;
   232,  32,  24,  16,   8;
   288,  40,  32,  24,  16,   8;
   688,  96,  80,  64,  48,  32,  16;
   800, 112,  96,  80,  64,  48,  32, 16;
  1824, 256, 224, 192, 160, 128,  96, 64, 32;
  2048, 288, 256, 224, 192, 160, 128, 96, 64, 32;

Maple

A145684 := proc(n, k) if k = 0 then 7*n-6 ; else n-k; end if; 2^(1+floor((n-1)/2))*% ; end proc: # R. J. Mathar, Sep 02 2011

Mathematica

Clear[e, n, k];
e[n_, 0] := 7*n - 6;
e[n_, k_] := 0 /; k >= n;
e[n_, k_] := (e[n - 1, k]*e[n, k - 1] + 1)/e[n - 1, k - 1];
Table[Table[2^(Floor[(n - 1)/2] + 1)*e[n, k], {k, 0, n - 1}], {n, 1, 10}];
Flatten[%]

Crossrefs

Sequence in context: A300138 A362884 A217028 * A254637 A197226 A141239

Adjacent sequences: A145681 A145682 A145683 * A145685 A145686 A145687

Keyword

nonn,tabl

Author

Roger L. Bagula and Gary W. Adamson, Mar 29 2009

Extensions

Description simplified by R. J. Mathar, Sep 02 2011

Status

approved