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A164280 a(n) is the sum of the first A129749(n) nonprimes. 2
1, 64, 800, 1452, 207143, 14934568, 18656679, 42721785, 889239450, 1991045973, 6684665064, 11847007536, 127880982508860, 262907426075600, 435646635220423, 58536266213035868, 1777764795352216572, 5690843954660983949, 190101452851104748107, 71537286176000166753366 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A variant of A050247 for nonprimes.

LINKS

Table of n, a(n) for n=1..20.

FORMULA

a(n) = sum_{i=1..A129749(n)} A018252(i).

EXAMPLE

A129749(4) = 44; sum of first 44 nonprimes is 1452, so a(4) = 1452.

PROG

(MAGMA) S:=[]; a:=0; c:=0; for n in [1..20000000] do if not IsPrime(n) then a+:=n; c+:=1; if a mod c eq 0 then Append(~S, a); end if; end if; end for; S;

CROSSREFS

Cf. A129749, A050247, A018252, A160758.

Sequence in context: A190532 A181889 A236182 * A232001 A185299 A250281

Adjacent sequences:  A164277 A164278 A164279 * A164281 A164282 A164283

KEYWORD

nonn

AUTHOR

Klaus Brockhaus, Aug 11 2009

EXTENSIONS

a(16)-a(19) from Donovan Johnson, Sep 19 2009

a(20) from Donovan Johnson, Jun 21 2011

STATUS

approved

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Last modified September 19 07:08 EDT 2021. Contains 347554 sequences. (Running on oeis4.)