303425domain: NAppears in sequencesExpansion of e.g.f.: sech(arctan(x)+log(x+1))=1-4/2!*x^2+6/3!*x^3+77/4!*x^4-340/5!*x^5...at n=8A012971Smallest positive integer m such that m, m+1, m+2, m+3 are divisible by 2n+1, 2n+3, 2n+5, 2n+7 respectively.at n=12A279259