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A153804
a(n) = A153801(n)/2.
1
0, 0, 0, 0, 1, 2, 1, 6, 19, 30, 38, 45, 240, 282, 616, 1075, 1111, 1578, 2093, 2176, 4808, 4931, 5565, 9924, 10802, 11554, 22197, 43068, 55197, 65968, 107982, 378354, 429648, 628824, 699060, 1488035, 1510610, 3486215, 6733375, 10497919, 12018202, 12982385, 15201133
OFFSET
1,6
LINKS
FORMULA
a(n) = (A000043(n) - A000040(n))/2.
MATHEMATICA
With[{max = 48}, (MersennePrimeExponent[Range[max]] - Prime[Range[max]]) / 2] (* Amiram Eldar, Oct 21 2024 *)
CROSSREFS
KEYWORD
nonn,changed
AUTHOR
Omar E. Pol, Jan 13 2009
EXTENSIONS
More terms from R. J. Mathar, Mar 14 2009
More terms from Jinyuan Wang, Mar 02 2020
STATUS
approved