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A090781 Numbers that can be expressed as the difference of the squares of primes in just one distinct way. 26
5, 16, 21, 24, 40, 45, 48, 96, 112, 117, 144, 160, 165, 192, 264, 280, 285, 288, 336, 352, 357, 504, 520, 525, 648, 816, 832, 837, 936, 952, 957, 1152, 1344, 1360, 1365, 1368, 1440, 1656, 1672, 1677, 1752, 1824, 1840, 1845, 1872, 1968, 2184, 2200, 2205, 2328 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

T. D. Noe, Table of n, a(n) for n=1..908

EXAMPLE

5 = 3^2-2^2.

MATHEMATICA

With[{nn=100}, Take[Sort[Transpose[Select[Tally[Last[#]-First[#]&/@ Subsets[ Prime[Range[nn]]^2, {2}]], Last[#]==1&]][[1]]], nn]] (* Harvey P. Dale, Apr 05 2014 *)

CROSSREFS

Cf. A078667, A090788, A090782.

Sequence in context: A204920 A168469 A124865 * A191264 A077469 A022140

Adjacent sequences:  A090778 A090779 A090780 * A090782 A090783 A090784

KEYWORD

nonn

AUTHOR

Ray Chandler, Feb 14 2004

STATUS

approved

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Last modified April 28 16:04 EDT 2017. Contains 285578 sequences.