

A033215


Primes of form x^2+21*y^2.


27



37, 109, 193, 277, 337, 373, 421, 457, 541, 613, 673, 709, 757, 877, 1009, 1033, 1093, 1117, 1129, 1201, 1213, 1297, 1381, 1429, 1453, 1549, 1597, 1621, 1789, 1801, 1873, 1933, 2017, 2053, 2137, 2221
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OFFSET

1,1


REFERENCES

David A. Cox, "Primes of the Form x^2 + n y^2", Wiley, 1989.


LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000


FORMULA

The primes are congruent to {1, 25, 37} (mod 84).  T. D. Noe, Apr 29 2008


MATHEMATICA

QuadPrimes[1, 0, 21, 10000] (* see A106856 *)


CROSSREFS

Cf. A139643.
Sequence in context: A139934 A142051 A171833 * A195316 A176549 A118536
Adjacent sequences: A033212 A033213 A033214 * A033216 A033217 A033218


KEYWORD

nonn,easy


AUTHOR

N. J. A. Sloane.


STATUS

approved



