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A061536
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a(1) = 1 and a(n) = a(n-1) + (the number of primes <= n) for n > 1.
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2
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1, 2, 4, 6, 9, 12, 16, 20, 24, 28, 33, 38, 44, 50, 56, 62, 69, 76, 84, 92, 100, 108, 117, 126, 135, 144, 153, 162, 172, 182, 193, 204, 215, 226, 237, 248, 260, 272, 284, 296, 309, 322, 336, 350, 364, 378, 393, 408, 423, 438, 453, 468, 484, 500, 516, 532, 548
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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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MATHEMATICA
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a[1] = 1; a[n_] := a[n - 1] + PrimePi[n]; Table[ a[n], {n, 1, 70} ]
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PROG
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(PARI) a=1; for (n=1, 100, print1(a+=primepi(n), ", ")) \\ Harry J. Smith, Jul 24 2009
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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