login
A096711
Number of balanced primes (A090403) less than 10^n.
3
1, 8, 57, 308, 1989, 13161, 94939
OFFSET
1,2
COMMENTS
The average number of balanced primes, p_n, seems to reach a maximum at the 85th prime, 439, of 32 balanced primes.
A096711(n)/A006880(n) begins 25%, 32%, 33.93%, 25.06%, 20.74%
MATHEMATICA
f[n_] := f[n] = Block[{c = 0, k = 1, p = Prime[n], s = Plus @@ Table[Prime[i], {i, n - 1, n + 1}]}, While[k != n - 1, If[s == (2k + 1)p, Return[1]]; k++; s = s + Prime[n - k] + Prime[n + k]]; 0]; f[1] = 0; Do[ f[n], {n, 10000}]; s = Prime[ Select[ Range[ 10000], f[ # ] == 1 &]]; Table[ Length[ Select[s, # < 10^n &]], {n, 5}]
CROSSREFS
Cf. A090403.
Sequence in context: A296721 A283693 A297453 * A282394 A244201 A079926
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Jul 03 2004
EXTENSIONS
a(6)-a(7) from Donovan Johnson, Apr 09 2010
STATUS
approved