A089221 a(n) = floor(sqrt(((prime(n) + primepi(n))/2)^2 + prime(n)*primepi(n))).

1, 2, 4, 5, 9, 10, 13, 14, 16, 19, 21, 25, 28, 29, 31, 34, 38, 39, 44, 46, 47, 50, 53, 56, 60, 62, 63, 65, 68, 70, 78, 80, 83, 84, 89, 90, 94, 98, 100, 103, 107, 108, 114, 115, 117, 118, 126, 132, 134, 135, 137, 140, 142, 147, 150, 153, 156, 157, 162, 164, 166, 171, 178

Offset

1,2

Links

Table of n, a(n) for n=1..63.

Mathematica

f[n_]=Floor[Sqrt[((Prime[n]+PrimePi[n])/2)^2+Prime[n]*PrimePi[n]]]
a=Table[f[n], {n, 1, 200}]

Crossrefs

Sequence in context: A289175 A274693 A024618 * A347877 A167180 A091271

Adjacent sequences: A089218 A089219 A089220 * A089222 A089223 A089224

Keyword

nonn,less

Author

Roger L. Bagula, Jan 03 2004

Status

approved