A145047 - OEIS

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A145047

Primes p of the form 4k+1 for which s=10 is the least positive integer such that sp-(floor(sqrt(sp)))^2 is a square.

1237, 1621, 1721, 1933, 1949, 1993, 2221, 2237, 2309, 2341, 2473, 2621, 2657, 2789, 2797, 2857, 2953, 3221, 3361, 3533, 3677, 3881, 3889, 3917, 4133, 4457, 4481, 4549, 4813, 4889, 4973, 5153, 5189, 5261, 5441, 5653, 5717, 5813, 6101, 6217, 6301, 6329

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OFFSET

1,1

COMMENTS

Conjecture: The least positive integer s can take values only from A008784 (see for s=1,2,5,10 sequences A145016, A145022, A145023 and this sequence).

LINKS

Table of n, a(n) for n=1..42.

EXAMPLE

a(1)=1237 since p=1237 is the least prime of the form 4k+1 for which sp-(floor(sqrt(sp)))^2 is not a square for s=1..9, but 10p-(floor(sqrt(10p)))^2 is a square (for p=1237 it is 49).

CROSSREFS

Cf. A145016, A145017, A145022, A145023, A008784.

Sequence in context: A122043 A179913 A161868 * A236974 A237552 A010081

Adjacent sequences: A145044 A145045 A145046 * A145048 A145049 A145050

KEYWORD

nonn

AUTHOR

Vladimir Shevelev, Sep 30 2008, Oct 05 2008

STATUS

approved