The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A228233 Number of Gaussian primes of norm less than or equal to n in the first quadrant. 4
 0, 1, 5, 7, 9, 11, 17, 21, 23, 27, 35, 37, 41, 47, 49, 55, 63, 69, 77, 83, 91, 97, 103, 109, 119, 127, 133, 143, 151, 159, 169, 179, 187, 199, 209, 219, 227, 237, 245, 251, 265, 279, 287, 301, 311, 323, 335, 351, 367, 377, 385, 401, 419, 431, 441, 455, 469 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Include 2 times the primes (once for the real axis, once for the imaginary axis). More precisely, a(n) includes all Gaussian primes (with the appropriate norms) on the first quadrant's bounding semi-axes. All such Gaussian primes occur in pairs {p, pi} (one real and one imaginary associate), where p is a classical prime of the form 4m + 3 (so p is in A002145) and p <= n. - Rick L. Shepherd, Jun 16 2017 LINKS T. D. Noe, Table of n, a(n) for n = 1..1000 MATHEMATICA nn = 100; t = Select[Flatten[Table[a + b*I, {a, 0, nn}, {b, 0, nn}]], PrimeQ[#, GaussianIntegers -> True] &]; t2 = Table[0, {nn}]; Do[f = Ceiling[Abs[i]]; If[f <= nn, t2[[f]]++], {i, t}]; Accumulate[t2] (* T. D. Noe, Aug 19 2013 *) CROSSREFS Cf. A000603 (number of Gaussian integers in the first quadrant with norm less than or equal to n). Cf. A062711 (counts the Gaussian primes on only one axis). Cf. A228232 (this sequence excluding classical primes and pure imaginary primes). Cf. A002145 (Gaussian primes that are positive integers). Sequence in context: A023380 A076190 A028885 * A256091 A229064 A024910 Adjacent sequences: A228230 A228231 A228232 * A228234 A228235 A228236 KEYWORD nonn AUTHOR Olivier Gérard, Aug 17 2013 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 4 12:12 EDT 2023. Contains 363128 sequences. (Running on oeis4.)