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.

A101301 The sum of the first n primes, minus n.

Original entry on oeis.org

1, 3, 7, 13, 23, 35, 51, 69, 91, 119, 149, 185, 225, 267, 313, 365, 423, 483, 549, 619, 691, 769, 851, 939, 1035, 1135, 1237, 1343, 1451, 1563, 1689, 1819, 1955, 2093, 2241, 2391, 2547, 2709, 2875, 3047, 3225, 3405, 3595, 3787, 3983, 4181, 4391, 4613, 4839
Offset: 1

Views

Author

Jorge Coveiro, Dec 22 2004

Keywords

Comments

Also: a(n) = sum_{k=1..n} phi(prime(k)).
Partial sums of A006093. - Omar E. Pol, Oct 31 2013
Difference minus n, between the constant term prime(n) for a polynomial P(x) built from the first n primes took as coefficients and the value that such term should have in order to make P(x) divisible by (x-1). See links. - R. J. Cano, Jan 14 2014
Sum of all deficiencies of the first n primes. - Omar E. Pol, Feb 21 2014

Crossrefs

Programs

  • Haskell
    a101301 n = a101301_list !! (n-1)
    a101301_list = scanl1 (+) a006093_list
    -- Reinhard Zumkeller, May 01 2013
    
  • Maple
    seq((sum(phi(ithprime(x)),k=1..n)),n=1..100);
  • Mathematica
    f[n_]:=Plus@@Prime[Range[n]]-n; Table[f[n],{n,1,50}] (* Enrique Pérez Herrero, Jun 10 2012 *)
  • PARI
    a(n)=my(s);forprime(p=2,prime(n),s+=p); s-n \\ Charles R Greathouse IV, Oct 31 2013
    
  • PARI
    \\ See links.

Formula

a(n)=sum_{k=1..n} (prime(k)-1)
a(n)=A007504(n)-n. - Juri-Stepan Gerasimov, Nov 23 2009
A027424(A000040(n)) < a(n). - Charles R Greathouse IV, Apr 07 2021

Extensions

Name simplified by Juri-Stepan Gerasimov, Nov 23 2009