OFFSET
1,2
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
LINKS
Enrique Pérez Herrero, Table of n, a(n) for n = 1..5000
R. J. Cano, Additional information
R. J. Cano, PARI/GP code: alternative sequencer
FORMULA
a(n)=sum_{k=1..n} (prime(k)-1)
a(n)=A007504(n)-n. - Juri-Stepan Gerasimov, Nov 23 2009
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 *)
PROG
(Haskell)
a101301 n = a101301_list !! (n-1)
a101301_list = scanl1 (+) a006093_list
-- Reinhard Zumkeller, May 01 2013
(PARI) a(n)=my(s); forprime(p=2, prime(n), s+=p); s-n \\ Charles R Greathouse IV, Oct 31 2013
(PARI) See links.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jorge Coveiro, Dec 22 2004
EXTENSIONS
Name simplified by Juri-Stepan Gerasimov, Nov 23 2009
STATUS
approved