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A094779
Let 2^k = smallest power of 2 >= binomial(n,[n/2]); a(n) = 2^k - binomial(n,[n/2]).
2
0, 0, 0, 1, 2, 6, 12, 29, 58, 2, 4, 50, 100, 332, 664, 1757, 3514, 8458, 16916, 38694, 77388, 171572, 343144, 745074, 1490148, 3188308, 6376616, 13496132, 26992264, 56658968, 113317936, 236330717, 472661434, 980680538, 1961361076, 4052366942, 8104733884
OFFSET
0,5
COMMENTS
Suggested by reading the Knuth article.
a(n+1) < a(n) for n = 8, 40, 162, 650... - Ivan Neretin, Jun 25 2015
REFERENCES
D. E. Knuth, Efficient balanced codes, IEEE Trans. Inform. Theory, 32 (No. 1, 1986), 51-53.
LINKS
EXAMPLE
C(30,15) = 155117520; 2^28 = 268435456; difference is 113317936.
MATHEMATICA
Table[-(b = Binomial[n, Quotient[n, 2]]) + 2^Ceiling[Log2[b]], {n, 0, 36}] (* Ivan Neretin, Jun 25 2015 *)
CROSSREFS
Sequence in context: A330455 A183467 A057582 * A093387 A324408 A229487
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jun 10 2004
STATUS
approved