A227994 Primes that are the sum of the squares of three integers that form an arithmetic sequence with difference 7.
461, 773, 1181, 1973, 2621, 6173, 7901, 9173, 11261, 21773, 29501, 37061, 44021, 50021, 51581, 54773, 58061, 66701, 68501, 72173, 75941, 81773, 85781, 96221, 109541, 118901, 126173, 143981, 204461, 210773, 220421, 233621, 236981, 254141, 279173, 286541, 328781, 336773
Offset: 1
Keywords
Examples
461 is a term since 4^2 + 11^2 + 18^2 = 461; 773 is a term since 8^2 + 15^2 + 22^2 = 773; 1181 is a term since 12^2 + 19^2 + 26^2 = 1181; 1973 is a term since 18^2 + 25^2 + 32^2 = 1973.
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..1000
Crossrefs
Subsequence of A085317. - Michel Marcus, Apr 01 2019
Programs
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Maple
for x in range(1, 2000): b=x**2 : c= (x+7)**2: d=(x+14)**2:e=(b+c+d): print x,e
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Mathematica
Select[Table[Total[(n+{0,7,14})^2],{n,500}],PrimeQ] (* Harvey P. Dale, Jun 10 2021 *) -
PARI
for(n=1,1e3,if(isprime(t=3*(n+7)^2+98),print1(t", "))) \\ Charles R Greathouse IV, Aug 14 2013
Extensions
a(14)-a(38) from Charles R Greathouse IV, Aug 14 2013
Name clarified by Jon E. Schoenfield, Apr 01 2019
Comments