The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Please make a donation to keep the OEIS running. We are now in our 56th year. In the past year we added 10000 new sequences and reached almost 9000 citations (which often say "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A064009 a(n) = Sum_{k=1..n} d(k)*prime(k), where d(k) = A001223. 1
 2, 8, 18, 46, 68, 120, 154, 230, 368, 426, 612, 760, 842, 1014, 1296, 1614, 1732, 2098, 2366, 2508, 2946, 3262, 3760, 4472, 4860, 5062, 5474, 5688, 6124, 7706, 8214, 9000, 9274, 10664, 10962, 11868, 12810, 13462, 14464, 15502, 15860, 17670, 18052 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Harry J. Smith, Table of n, a(n) for n=1..1000 EXAMPLE a(4) = 2*(3-2) + 3*(5-3) + 5*(7-5) + 7*(11-7) = 46. MATHEMATICA Accumulate@ Array[# (NextPrime@ # - #) &@ Prime@ # &, {43}] (* Michael De Vlieger, May 05 2016 *) PROG (PARI) d(n) = prime(n+1)-prime(n); j=[]; for(n=1, 150, j=concat(j, sum(k=1, n, prime(k)*d(k)))); j (PARI) d(n)= { prime(n + 1) - prime(n) } { a=0; for (n=1, 1000, write("b064009.txt", n, " ", a+=prime(n)*d(n)) ) } \\ Harry J. Smith, Sep 05 2009 (Sage) p=primes_first_n(44); d=differences(p); v=[]; a=0 for k in range(len(d)):    a+=p[k]*d[k]; v.append(a) print(v)  # Giuseppe Coppoletta, May 05 2016 CROSSREFS Cf. A001223. Sequence in context: A212518 A264054 A073307 * A246148 A201348 A102713 Adjacent sequences:  A064006 A064007 A064008 * A064010 A064011 A064012 KEYWORD nonn AUTHOR Jason Earls, Sep 06 2001 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 5 00:42 EST 2020. Contains 338943 sequences. (Running on oeis4.)