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A046992
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a(n) = sum_{k=1..n} pi(k) (cf. A000720).
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8
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0, 1, 3, 5, 8, 11, 15, 19, 23, 27, 32, 37, 43, 49, 55, 61, 68, 75, 83, 91, 99, 107, 116, 125, 134, 143, 152, 161, 171, 181, 192, 203, 214, 225, 236, 247, 259, 271, 283, 295, 308, 321, 335, 349, 363, 377, 392, 407, 422, 437, 452, 467, 483, 499, 515, 531, 547, 563, 580, 597, 615, 633, 651, 669
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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LINKS
| T. D. Noe, Table of n, a(n) for n=1..1000
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FORMULA
| O.g.f.: A(x)/(1-x)^2 where A(x)=Sum_{p=prime}x^p is the o.g.f. of A010051 and A(x)/(1-x) is the o.g.f. of A000720. - Geoffrey Critzer, Dec 04 2011.
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MATHEMATICA
| f[n_] := (f[n - 1] + PrimePi[n]); f[1] = 0; Table[ f[n], {n, 1, 60}]
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CROSSREFS
| Sequence in context: A003311 A108279 A002821 * A001463 A145197 A024169
Adjacent sequences: A046989 A046990 A046991 * A046993 A046994 A046995
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KEYWORD
| nonn,easy,nice
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Robert G. Wilson v (rgwv(AT)rgwv.com)
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EXTENSIONS
| Corrected by Henry Bottomley (SE16(AT)btinternet.com)
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