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A153048 Numbers n with property that n^2 is a concatenation of two 3-digit primes. 5
319, 337, 357, 363, 371, 387, 409, 447, 591, 663, 681, 701, 801, 827, 893 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

There are exactly 15 such numbers.

LINKS

Table of n, a(n) for n=1..15.

EXAMPLE

Corresponding squares are: 101761, 113569, 127449, 131769, 137641, 149769, 167281, 199809, 349281, 439569, 463761, 491401, 641601, 683929, 797449.

MATHEMATICA

c = 0; t = 1000; re = Sort[Reap[Do[If[PrimeQ[p], Do[If[PrimeQ[q], r = p*t + q; s = Sqrt[r]; If[s == Floor[s], c++; Sow[s]]], {q, 101, 999, 2}]], {p, 101, 999, 2}]][[2, 1]]]

CROSSREFS

Sequence in context: A225579 A261281 A126838 * A053020 A250660 A252410

Adjacent sequences:  A153045 A153046 A153047 * A153049 A153050 A153051

KEYWORD

fini,full,nonn,base

AUTHOR

Zak Seidov, Dec 17 2008

STATUS

approved

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Last modified June 1 19:32 EDT 2020. Contains 334762 sequences. (Running on oeis4.)