A130272 Primes p for which the period of the continued fraction of sqrt(p) increases.

2, 3, 7, 13, 19, 31, 43, 61, 103, 109, 139, 151, 181, 211, 331, 421, 541, 571, 631, 751, 919, 1291, 1381, 1549, 1579, 1621, 1759, 1831, 2011, 2311, 2671, 3019, 3469, 3691, 3931, 4909, 4951, 4999, 5119, 6211, 6451, 6679, 8269, 8719, 8779, 8941, 9739, 9949

Offset

1,1

Links

Chai Wah Wu, Table of n, a(n) for n = 1..344 (terms n = 1..200 from T. D. Noe)

Formula

Where records occur in A054269.

Mathematica

mx=0; n=0; t=Table[n++; While[p=Prime[n]; len=Length[Last[ContinuedFraction[Sqrt[p]]]]; len<=mx, n++ ]; mx=len; p, {50}]

Crossrefs

Cf. A003285, A013645.

Sequence in context: A045331 A053613 A013645 * A331948 A342529 A172238

Adjacent sequences: A130269 A130270 A130271 * A130273 A130274 A130275

Keyword

nonn

Author

T. D. Noe, May 19 2007

Status

approved