1,3

Table of n, a(n) for n=1..11.

Take the absolute value of the difference between counts of runs of 3 primes congruent to 1 mod 4 and 3 mod 4.

a(3)=3 because in A092642 the count is 4 and in A092643 the count is 1. 4 - 1 = 3.

Cf. A092642, A092643.

Sequence in context: A173795 A249769 A026345 * A006281 A157705 A185447

Adjacent sequences: A092641 A092642 A092643 * A092645 A092646 A092647

more,nonn

Enoch Haga, Mar 02 2004

a(9)-a(11) from Chai Wah Wu, Mar 18 2018

approved