cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A053767 Sum of first n composite numbers.

Original entry on oeis.org

0, 4, 10, 18, 27, 37, 49, 63, 78, 94, 112, 132, 153, 175, 199, 224, 250, 277, 305, 335, 367, 400, 434, 469, 505, 543, 582, 622, 664, 708, 753, 799, 847, 896, 946, 997, 1049, 1103, 1158, 1214, 1271, 1329, 1389, 1451, 1514, 1578, 1643, 1709, 1777, 1846, 1916, 1988
Offset: 0

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Author

G. L. Honaker, Jr., Mar 29 2000

Keywords

Comments

a(A196415(n)) = A036691(A196415(n)) / A141092(n). - Reinhard Zumkeller, Oct 03 2011

Crossrefs

First differences of A023539.

Programs

  • Haskell
    a053767 n = a053767_list !! (n-1)
    a053767_list = scanl1 (+) a002808_list -- Reinhard Zumkeller, Oct 03 2011
    
  • Maple
    A053767 := proc(n)
            add(A002808(i),i=1..n) ;
    end proc: # R. J. Mathar, Oct 03 2011
    ListTools[PartialSums](remove(isprime,[$2..1000])); # Robert Israel, Jan 09 2015
  • Mathematica
    lst={};s=0;Do[If[ !PrimeQ[n], s=s+n;AppendTo[lst, s]], {n, 2, 10^2}];lst (* Vladimir Joseph Stephan Orlovsky, Aug 14 2008 *)
    Accumulate[Complement[Range[2,100],Prime[Range[PrimePi[100]]]]] (* Harvey P. Dale, Dec 28 2010 *)
    Accumulate[Select[Range[2, 100], ! PrimeQ[#] &]]
  • PARI
    lista(nn) = {my(s=0); forcomposite(n=0, nn, print1(s, ", "); s += n;);} \\ Michel Marcus, Jan 09 2015

Formula

a(n) = A000217(A002808(n)) - A034387(A002808(n)) - 1 . - Robert Israel, Jan 09 2015
a(n) = A051349(n+1) - 1. - Michel Marcus, Feb 16 2018

Extensions

a(0)=0 prepended by Max Alekseyev, Feb 10 2018