-3,1

a(n) = Min[s in A001358 and A002321(s) = n].

a(-3) = 33 = 3 * 11 = the first semiprime s for which the Mertens function M(s) = -3.

a(-2) = 9 = 3^2 = the first semiprime s for which the Mertens function M(s) = -2.

a(-1) = 4 = 2^2 = the first semiprime s for which the Mertens function M(s) = -1.

a(0) = 39 = 3 * 13 = Min[A001358 INTERSECTION A028442] = the first semiprime s for which the Mertens function M(s) = 0.

a(1) = 94 = 2 * 47 = Min[A001358 INTERSECTION A118684] = the first semiprime s for which the Mertens function M(s) = 1.

a(2) = 95 = 5 * 19 = the first semiprime s for which the Mertens function M(s) = 2.

a(3) = 341 = 11 * 31 = the first semiprime s for which the Mertens function M(s) = 3.

Cf. A001358, A002321, A028442, A118684.

Sequence in context: A113467 A113458 A120584 this_sequence A138839 A033353 A104781

Adjacent sequences: A123170 A123171 A123172 this_sequence A123174 A123175 A123176

easy,nonn

Jonathan Vos Post (jvospost2(AT)yahoo.com), Oct 02 2006