OFFSET
1,2
COMMENTS
Conjecture: Asymptotic density of nonzero terms is 3/4.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..1000
J. Sondow, Ramanujan Prime. (MathWorld)
MATHEMATICA
nn = 100;
R = Table[0, {nn}]; s = 0;
Do[If[PrimeQ[k], s++]; If[PrimeQ[k/2], s--]; If[s < nn, R[[s+1]] = k], {k, Prime[3nn]}
];
A104272 = R = R + 1;
T = Table[0, {nn + 1}]; s = 0;
Do[If[PrimeQ[k], s++]; If[PrimeQ[k/2], s--]; If[s <= nn && T[[s+1]] == 0, T[[s+1]] = k], {k, Prime[3nn]}
];
A080359 = Rest[T];
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Aug 18 2011
STATUS
approved