A007601 Positions where A007600 increases.

1, 2, 3, 4, 5, 7, 10, 13, 19, 28, 37, 55, 82, 109, 163, 244, 325, 487, 730, 973, 1459, 2188, 2917, 4375, 6562, 8749, 13123, 19684, 26245, 39367, 59050, 78733, 118099, 177148, 236197, 354295, 531442, 708589, 1062883, 1594324, 2125765, 3188647

Offset: 1

Author

N. J. A. Sloane, Robert G. Wilson v, and Mira Bernstein

Keywords

• nonn
• easy
• changed

References

• R. Honsberger, Mathematical Gems III, M.A.A., 1985, p. 225.
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• Eric Weisstein's World of Mathematics, Katona's Problem

Crossrefs

Cf. A000792.

Programs

Mathematica

f[n_] := Min[ Table[2p + 3Ceiling[Log[3, n/2^p]], {p, 0, 2}]]; g[1] = 1; g[n_] := g[n] = Block[{k = g[n - 1]}, While[ f[k] != n, k++ ]; k]; Table[ g[n], {n, 2, 15}] (* Robert G. Wilson v, Jan 15 2005 *)

Formula

a(n) = A000792(n-1)+1 for n>1. - Harry Altman, May 17 2011

Extensions

More terms from Robert G. Wilson v, Jan 15 2005