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A065595
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a(n) = (sum of first n primes)^2 - sum of squares of first n primes.
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3
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0, 12, 62, 202, 576, 1304, 2698, 4902, 8444, 14244, 22242, 34082, 50236, 70704, 97118, 131886, 176844, 230524, 297658, 378314, 471608, 584104, 715410, 870982, 1057804, 1271924, 1511090, 1781586, 2080464, 2414944, 2819566, 3270206
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OFFSET
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1,2
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LINKS
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FORMULA
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EXAMPLE
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a(4) = 202 because (2 + 3 + 5 + 7)^2 - (2^2 + 3^2 + 5^2 + 7^2) = 17^2 - (4 + 9 + 25 + 49) = 289 - 87 = 202
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MATHEMATICA
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With[{prs=Prime[Range[40]]}, Table[Total[Take[prs, n]]^2-Total[Take[ prs, n]^2], {n, 40}]] (* Harvey P. Dale, Dec 04 2011 *)
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PROG
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(PARI) { a1=a2=0; for (n=1, 500, a1+=prime(n); a2+=prime(n)^2; write("b065595.txt", n, " ", a1^2 - a2) ) } \\ Harry J. Smith, Oct 23 2009
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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