OFFSET
1,1
LINKS
R. J. Mathar, Table for d <= 1000 (PDF)
FORMULA
T(n,1) = 2.
lim n->inf (a(n)/n) = SUM(p prime; (p-1)/(#(p-1)) = 2.92005097731613471209+
EXAMPLE
Table begins:
d \k|..1..2..3..4..5..
----+-----------------
..1.|..2..2
..2.|..2..3..3
..3.|..2..2
..4.|..2..3..3
..5.|..2..2
..6.|..2..5..5..5..5
..7.|..2
..8.|..2..3..3
..9.|..2..2
.10.|..2..3..3
.11.|..2..2
.12.|..2..5..5..5..5
.13.|..2
.14.|..2..3..3
.15.|..2..2
.16.|..2..3
.17.|..2..2
.18.|..2..5..5..5
.19.|..2
.20.|..2..3..3
T(24,4) = 59 since (59,83,107,131) is the first A.P. of 4 primes with difference 24.
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
R. J. Mathar, Nov 04 2006
EXTENSIONS
Edited by David W. Wilson, Nov 05 2006 and Nov 25 2006
STATUS
approved