OFFSET
0,2
REFERENCES
D. L. Kreher and D. R. Stinson, Combinatorial Algorithms, CRC Press, 1999, p. 113.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
EXAMPLE
1, 2, 7/2, 45/8, 545/64, 12625/1024, 564929/32768, 49162689/2097152, ...
MAPLE
f := n->add(binomial(n, k)/2^(k*(k-1)/2), k=0..n);
MATHEMATICA
Table[Round[Sum[Binomial[n, k]/2^(k*(k-1)/2), {k, 0, n}]], {n, 0, 60}] (* G. C. Greubel, Jan 18 2019 *)
PROG
(PARI) vector(60, n, n--; round(sum(k=0, n, binomial(n, k)/2^(k*(k-1)/2)))) \\ G. C. Greubel, Jan 18 2019
(Magma) [Round( (&+[Binomial(n, k)/2^(k*(k-1)/2): k in [0..n]]) ): n in [0..60]]; // G. C. Greubel, Jan 18 2019
(Sage) [round(sum(binomial(n, k)/2^(k*(k-1)/2) for k in (0..30))) for n in (0..60)] # G. C. Greubel, Jan 18 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 20 2003
STATUS
approved