OFFSET
1,1
COMMENTS
a(1) = 4 and a(6) = 441 are perfect squares. What is the next term in this subsequence? Answer from Stefan Steinerberger: a(103)=315844=562^2.
REFERENCES
Bach, E. and Shallit, J. Sect. 2.7 in Algorithmic Number Theory, Vol. 1: Efficient Algorithms. Cambridge, MA: MIT Press, 1996.
H. L. Nelson, "Prime Sums", J. Rec. Math., 14 (1981), 205-206.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
Leo Moser, Notes on number theory. III. On the sum of consecutive primes, Canad. Math. Bull. 6 (1963), pp. 159-161.
Eric Weisstein's World of Mathematics, Prime Sums.
FORMULA
EXAMPLE
MATHEMATICA
s = 0; lst = {}; Do[s = s + Prime[n]; If[Mod[s, 7] == 0, AppendTo[lst, s/7]], {n, 270}]; lst (* Robert G. Wilson v *)
Select[Accumulate[Prime[Range[300]]]/7, IntegerQ] (* Harvey P. Dale, Nov 26 2014 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Nov 30 2005
EXTENSIONS
More terms from Stefan Steinerberger and Robert G. Wilson v, Dec 02 2005
STATUS
approved