A145023 Primes p of the form 4k+1 for which s=5 is the least positive integer such that s*p - floor(sqrt(s*p))^2 is a perfect square.
353, 373, 449, 461, 521, 541, 593, 653, 673, 757, 769, 797, 821, 829, 941, 953, 1009, 1021, 1061, 1069, 1097, 1193, 1217, 1249, 1277, 1361, 1381, 1481, 1489, 1549, 1597, 1613, 1657, 1669, 1693, 1709, 1733, 1777, 1801, 1877, 1889, 1973, 2053, 2069, 2081
Offset: 1
Keywords
Examples
a(1)=353 since p=353 is the least prime of the form 4k+1 for which s*p - (floor(sqrt(s*p)))^2 is not a perfect square for s=1,...,4, but 5*p - (floor(sqrt(5*p)))^2 is a perfect square (for p=353 it is 1).
Programs
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PARI
s=[]; forprime(p=2, 3000, if(p%4==1 && !issquare(p-sqrtint(p)^2) && !issquare(2*p-sqrtint(2*p)^2) && !issquare(3*p-sqrtint(3*p)^2) && !issquare(4*p-sqrtint(4*p)^2) && issquare(5*p-sqrtint(5*p)^2), s=concat(s, p))); s \\ Colin Barker, Jul 23 2014
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