OFFSET
1,1
COMMENTS
Partial sums of A001043.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = 2sum(prime(i), i = 1 .. n) - (2 + prime(n)). - Alonso del Arte, Apr 21 2016
EXAMPLE
a(1) = 5 = (2+3).
a(2) = 13 = (2+3) + (3+5).
a(3) = 25 = (2+3) + (3+5) + (5+7).
MATHEMATICA
Table[Sum[Prime[i] + Prime[i + 1], {i, n}], {n, 47}] (* Ray Chandler, Feb 12 2005 *)
Table[2Sum[Prime[i], {i, n}] - (2 + Prime[n]), {n, 2, 50}] (* Alonso del Arte, Apr 26 2016 *)
Accumulate[Total/@Partition[Prime[Range[50]], 2, 1]] (* Harvey P. Dale, Apr 13 2019 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Giovanni Teofilatto, Feb 07 2005
EXTENSIONS
Edited and extended by Ray Chandler, Feb 12 2005
Better definition from Alonso del Arte, Apr 26 2016
STATUS
approved