1,2

Generate the odd nonprime sequence with nonprimes labeled 1 mod 4 or 3 mod 4. Add count of nonprimes to sequence if just 1 nonprime congruent to 1 mod 4 occurs before interruption of a nonprime congruent to 3 mod 4.

a(3)=74 because 74 single nonprime runs occur below 10^3, each run interrupted by a nonprime congruent to 3 mod 4

Cf. A093184 A093185 A093186 A093187 A093187 A093188 A093397 A093398 A093399 A092636.

Sequence in context: A002667 A145675 A162601 this_sequence A125520 A163131 A060869

Adjacent sequences: A093180 A093181 A093182 this_sequence A093184 A093185 A093186

easy,more,nonn

Enoch Haga (Enokh(AT)comcast.net), Mar 30 2004