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 A114410 Cumulative sum of double primorials (A079078). 1
 1, 3, 6, 16, 37, 147, 420, 2290, 7477, 50487, 200910, 1534220, 7099871, 61765581, 301088574, 2870376944, 15554495573, 167142509403, 940873745772, 11097270672382, 66032188454581, 807449164097111, 5147307668890832 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The cumulative sum is prime for a(2) = 3, a(4) = 37, a(8) = 7477, a(12) = 7099871, a(16) = 15554495573. The sum a(n) is semiprime for n = 2, 9. LINKS FORMULA a(n) = 0## + 1## + ... + n##, where n## = p(n)*(n-2)##, where p(n) is the n-th prime. EXAMPLE n 0## + ... + n## 0 1. 1 1+2 = 3. 2 1+2+3 = 6. 3 1+2+3+10 = 16. 4 1+2+3+10+21 = 37. 5 1+2+3+10+21+110 = 147. 6 1+2+3+10+21+110+273 = 420. 7 1+2+3+10+21+110+273+1870 = 2290. 8 1+2+3+10+21+110+273+1870+5187 = 7477. 9 1+2+3+10+21+110+273+1870+5187+ 43010 = 50487. 10 1+2+3+10+21+110+273+1870+5187+ 43010 + 150423 = 200910. MATHEMATICA p[0]=1; p[1]=2; p[n_] := p[n] = Prime[n]*p[n - 2]; Accumulate[p /@ Range[0, 22]] (* Giovanni Resta, Jun 14 2016 *) CROSSREFS Cf. A079078. Sequence in context: A027852 A203068 A321229 * A190735 A096588 A256943 Adjacent sequences:  A114407 A114408 A114409 * A114411 A114412 A114413 KEYWORD easy,nonn AUTHOR Jonathan Vos Post, Feb 12 2006 EXTENSIONS Data corrected by Giovanni Resta, Jun 14 2016 STATUS approved

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Last modified July 3 01:56 EDT 2022. Contains 355029 sequences. (Running on oeis4.)