OFFSET
1,1
COMMENTS
Contrast A057207, where all the factors are congruent to 1 (mod 4), here only one is guaranteed to be congruent to 3 (mod 4).
REFERENCES
Dirichlet,P.G.L (1871): Vorlesungen uber Zahlentheorie. Braunschweig, Viewig, Supplement VI, 24 pages.
G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers. 3rd ed., Oxford Univ. Press, 1954, p. 13.
LINKS
Daran Gill, Table of n, a(n) for n = 1..51
Mersenne Forum, Two new sequences
EXAMPLE
a(10) is 205677423255820459 because it is the only prime factor congruent to 3 (mod 4) of 4*(3*7*43*19*6863*883*23*191*2927)^2-1 = 5*13*2088217*256085119729*205677423255820459. The four smaller factors are all congruent to 1 (mod 4).
CROSSREFS
KEYWORD
nonn
AUTHOR
Daran Gill, Mar 23 2013
STATUS
approved