login
A228543
a(n) is the integer-valued average gap between successive primes from prime(1) to prime(k(n)), where k(n) = A049036(n).
2
1, 3, 5, 7, 7, 9, 13, 13, 13, 15, 15, 19, 19, 19, 19, 19, 21, 21, 27, 29, 31
OFFSET
1,2
COMMENTS
a(n) arises from A049036 and A049038.
FORMULA
a(n) = (A049038(n)-2)/(A049036(n)-1).
EXAMPLE
For n=1 a(n)=(p(k(1))-2)/(k(1)-1), where k(1)=2, p(2)=3, and a(1)=1;
For n=2 a(n)=(p(k(2))-2)/(k(2)-1), where k(2)=10, p(10)=29, and a(2)=3;
For n=3 a(n)=(p(k(3))-2)/(k(3)-1), where k(3)=68, p(68)=337, and a(3)=5;
MATHEMATICA
a = {}; Do[s = (Prime[k] - 2)/(k - 1); If[IntegerQ[s], AppendTo[a, s]], {k, 2, 1000000000}]; a
CROSSREFS
Sequence in context: A261010 A064002 A195868 * A367928 A254764 A109535
KEYWORD
nonn,more
AUTHOR
V.J. Pohjola, Aug 25 2013
STATUS
approved