|
Search: id:A087904
|
|
|
| A087904 |
|
a(n) = the number of twin primes j*(p(n)#)+-1, for 1<=j<(p(n+1))^2. |
|
+0
1
|
|
| 3, 10, 16, 19, 30, 40, 34, 45, 49, 47, 55, 53, 52, 53, 63, 74, 75, 68, 77, 73, 72, 73, 79, 95, 77, 67, 72, 84, 75, 94, 92, 96, 97, 100, 100, 94, 93, 107, 91, 92, 78
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
COMMENT
|
p(n) is the n-th prime; # denotes primorial (A002110).
|
|
FORMULA
|
a(n) seems to grow like 16 log p(n).
|
|
EXAMPLE
|
a(2)=10 because for j in {1,2,3,5,7,10,12,17,18,23}, j*(3#)+-1 are primes.
|
|
CROSSREFS
|
Cf. A002110.
Sequence in context: A037345 A051420 A092827 this_sequence A093516 A063209 A063109
Adjacent sequences: A087901 A087902 A087903 this_sequence A087905 A087906 A087907
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Pierre CAMI (colettecami(AT)aol.com), Oct 14 2003
|
|
EXTENSIONS
|
Edited by Don Reble (djr(AT)nk.ca), Nov 16 2005
|
|
|
Search completed in 0.002 seconds
|
