A113426 Greatest prime closest to n^2.

2, 5, 11, 17, 23, 37, 47, 67, 83, 101, 127, 149, 167, 197, 227, 257, 293, 331, 359, 401, 443, 487, 523, 577, 631, 677, 727, 787, 839, 907, 967, 1021, 1091, 1153, 1223, 1297, 1367, 1447, 1523, 1601, 1693, 1759, 1847, 1933, 2027, 2113, 2207, 2309, 2399, 2503

Offset

1,1

Comments

A060272(n) = abs(A000290(n) - a(n));

A113425(n) <= a(n).

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Mathematica

f[n_]:=Module[{n2=n^2, np1, np2}, np1=NextPrime[n2, -1]; np2=NextPrime[n2]; If[(n2-np1)<(np2-n2), np1, np2]]
Table[f[i], {i, 50}]

Crossrefs

Sequence in context: A020613 A135478 A019381 * A078894 A086319 A220813

Adjacent sequences: A113423 A113424 A113425 * A113427 A113428 A113429

Keyword

nonn

Author

Reinhard Zumkeller, Oct 31 2005

Status

approved