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A154880
First prime in a consecutive sequence of 4 primes such that, when taken as ordered x,y pairs, the Cartesian distance between the two points is an integer.
1
2, 67, 239, 241, 283, 331, 547, 577, 769, 829, 1033, 1171, 1399, 1447, 1493, 1601, 1621, 1759, 1933, 2011, 2213, 2243, 2377, 2591, 2609, 2707, 2713, 2749, 2887, 3259, 3511, 3541, 3769, 3793, 3823, 3853, 3911, 4241, 4271, 4373, 4391, 4423, 4651, 4673
OFFSET
1,1
LINKS
EXAMPLE
a(1)=2 because the distance between (2,3) and (5,7) is 5. a(2)=67 because the distance between (67,71) and (73,79) is 10.
MATHEMATICA
cdQ[{a_, b_, c_, d_}]:=IntegerQ[Sqrt[(a-c)^2+(b-d)^2]]; Transpose[Select[ Partition[ Prime[Range[700]], 4, 1], cdQ]][[1]] (* Harvey P. Dale, Mar 23 2015 *)
CROSSREFS
Sequence in context: A107214 A371509 A174602 * A160958 A046848 A318064
KEYWORD
easy,nonn
AUTHOR
Gil Broussard, Jan 16 2009
STATUS
approved