A272205 A bisection of the primes congruent to 1 modulo 3 (A002476). This is the part depending on the corresponding A001479 entry being congruent to 4 or 5 modulo 6.

19, 37, 43, 73, 103, 127, 163, 229, 283, 313, 331, 337, 379, 397, 421, 457, 463, 487, 499, 523, 541, 577, 607, 613, 619, 631, 691, 709, 727, 787, 811, 829, 853, 859, 877, 883, 967, 991, 997

Offset: 1

Author

Wolfdieter Lang, May 05 2016

Keywords

• nonn
• easy

Comments

The other part of this bisection appears in A272204.

Each prime == 1 (mod 3) has a unique representation A002476(m) = A(m)^2 + 3*B(m)^2 with positive A(m) = A001479(m+1) and B(m) = A001480(m+1), m >= 1. The present sequence gives such primes corresponding to A(m) == 4, 5 (mod 6). The ones corresponding to A(m) == 1, 2 (mod 6) (the complement) are given in A272205.

The corresponding A001479 entries are 4, 5, 4, 5, 10, 10, 4, 11, 16, 11, 16, 17, 4, 17, 11, 5, 10, 22, 16, 4, 23, 23, 10, 5, 16, 22, 4, 11, 22, 28, 28, 23, 29, 28, 17, 4, 10, 22, 5, ...

See A272204 for a comment on the relevance of this bisection in connection with the signs of the q-expansion coefficients of the modular cusp form eta^{12}(12*z) / (eta^4(6*z)*eta^4(24*z)).

Crossrefs

Cf. A001479, A001480, A002476, A047239, A187076, A272203, A272204 (complement relative to A002476).

Formula

This sequence collects the 1 (mod 3) primes p(m) = A002476(m) = A(m)^2 + 3*B(m)^2 with positive A(m) == 4, 5 (mod 6), for m >= 1. A(m) = A001479(m+1).