A114564 Numbers of the form n=12s+7, where q=4s+3 is a prime for which the order of 2 is either q-1 or (q-1)/2.

7, 19, 31, 55, 67, 139, 175, 199, 211, 235, 247, 307, 319, 391, 415, 487, 499, 535, 571, 595, 631, 679, 715, 787, 811, 931, 1039, 1075, 1099, 1135, 1147, 1255, 1327, 1387, 1399, 1435, 1459, 1471, 1507, 1567, 1639, 1687, 1759, 1795, 1819, 1855

Offset: 1

Author

R. K. Guy, Feb 11 2006

Keywords

• nonn

References

• L. Heffter, Über das Problem der Nachbargebiete, Math. Ann., 38 (1891) 477-508.
• G. Ringel, Map Color Theorem, Springer, 1974, p. 6.

Crossrefs

Equals 3*A105876(n) - 2.