OFFSET
0,3
REFERENCES
Mark Heap, On the exact ordered binary decision diagram size of totally symmetric functions, Journal of Electronic Testing 4 (1993), 191-195.
Ingo Wegener, Optimal decision trees and one-time-only branching programs for symmetric Boolean functions, Information and Control 62 (1984), 129-143.
FORMULA
a(n) = sum_{k=1..n} min(k,2^{n+2-k}-2).
MATHEMATICA
f[n_] := Sum[ Min[k, 2^{n + 2 - k} - 2], {k, n}]; Table[ f@n, {n, 0, 57}] (* Robert G. Wilson v, Sep 16 2007 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Don Knuth, Sep 06 2007
STATUS
approved