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Search: id:A102696
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| A102696 |
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Number of positive even integers that can be written as the sum of 2 of the first n odd primes (not necessarily distinct). |
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+0
1
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| 1, 3, 5, 8, 11, 14, 17, 20, 23, 28, 32, 37, 40, 44, 47, 50, 57, 61, 66, 70, 73, 78, 83, 89, 94, 99, 103, 107, 110, 117, 122, 127, 134, 139, 144, 150, 154, 160, 165, 170, 177, 181, 187, 192, 196, 202, 207, 215, 220, 227, 231, 236, 242, 247, 250, 253, 261, 269, 274, 278
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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a(3) = 5 because with the primes {3, 5, 7} one can write 6 = 3+3, 8 = 3+5, 10 = 5+5, 12 = 5+7, and 14 = 7+7, for a total of 5 even numbers.
a(3) = 5 because with the primes {3, 5, 7} one can write 6 = 3+3, 8 = 3+5, 10 = 5+5 & 3+7, 12 = 5+7 and 14 = 7+7, for a total of 5 even numbers.
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MATHEMATICA
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f[n_] := Block[{tp = Table[ Prime[i], {i, 2, n + 1}]}, Length[ Union[ Flatten[ Table[tp[[i]] + tp[[j]], {i, n}, {j, i}]] ]]]; Table[ f[n], {n, 60}] (from Robert G. Wilson v Feb 05 2005)
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CROSSREFS
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Sequence in context: A076829 A084505 A084555 this_sequence A130262 A094228 A001855
Adjacent sequences: A102693 A102694 A102695 this_sequence A102697 A102698 A102699
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KEYWORD
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easy,nonn
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AUTHOR
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Gabriel Cunningham (gcasey(AT)mit.edu), Feb 04 2005
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Feb 05 2005
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