A109163 a(n) = A019565(n-th prime).
3, 6, 10, 30, 42, 70, 22, 66, 330, 770, 2310, 130, 182, 546, 2730, 1430, 6006, 10010, 102, 510, 238, 3570, 1122, 2618, 442, 2210, 6630, 9282, 15470, 4862, 510510, 114, 266, 798, 2090, 6270, 14630, 1482, 7410, 17290, 16302, 27170, 570570, 646, 3230
Offset: 1
Keywords
Examples
The 5th prime is 11 (decimal), which is 1011 in binary. So a(5) is the product of the primes corresponding to the 1's of 1011, 2*3*7 = 42.
Crossrefs
Cf. A019565.
Programs
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Mathematica
Table[m = 1; o = 1; k1 = Prime[k]; While[k1 > 0, k2 = Mod[k1, 2]; If[k2 == 1, m = m*Prime[o]]; k1 = (k1 - k2)/2; o = o + 1]; m, {k, 1, 55}] (* Stefan Steinerberger, Mar 19 2006 *)
Extensions
More terms from Stefan Steinerberger, Mar 19 2006