A289898 a(n) = floor((2^prime(n+1))/Sum_{k=0|n,2^prime(k)}).
2, 2, 2, 11, 3, 12, 3, 12, 59, 3, 51, 15, 3, 12, 59, 62, 3, 51, 15, 3, 50, 15, 60, 251, 15, 3, 12, 3, 12, 15179, 15, 60, 3, 816, 3, 51, 62, 15, 60, 62, 3, 816, 3, 12, 3, 3226, 4094, 15, 3, 12, 59, 3, 816, 63, 63, 63, 3, 51, 15, 3, 808, 16363, 15, 3, 12, 15183
Offset: 1
Keywords
Programs
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Mathematica
Table[Floor[2^Prime[n + 1]/Sum[ 2^Prime[k], {k, n}]], {n, 66}] (* Michael De Vlieger, Jul 16 2017 *) -
PARI
a(n) = 2^prime(n+1)\sum(k=1, n, 2^prime(k)); \\ Michel Marcus, Jul 16 2017
Formula
a(n) = floor(2^prime(n+1)/(Sum_{k=1..n} 2^prime(k))).