|
Search: id:A127270
|
|
|
| A127270 |
|
Suppose the sum of the composites between prime(n) and prime(n+2) is prime. Sequence gives prime(n). |
|
+0
2
|
|
| 19, 79, 229, 271, 349, 359, 373, 677, 733, 743, 751, 797, 937, 1231, 1279, 1459, 1489, 1549, 1733, 1789, 1801, 1973, 1979, 2069, 2539, 2693, 2777, 2791, 2837, 2857, 3061, 3083, 3191, 3329, 3557, 3559, 3659, 3691, 3719, 3919, 3929, 3989, 4129, 4283, 4447
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
EXAMPLE
|
The composites between prime(8) = 19 and prime(10) = 29 are 20, 21, 22, 24, 25, 26, 27, 28. Their sum 193 is prime, hence prime(8) = 19 is a term.
|
|
MATHEMATICA
|
Do[p = Prime[n]; If[PrimeQ[Apply[Plus, Select[Table[i, {i, p + 1, Prime[n + 2] - 1}], Not[PrimeQ[ # ]] &]]], Print[p]], {n, 1, 1000}] - Michael Taktikos (michael.taktikos(AT)hanse.net), Apr 01 2007
|
|
PROGRAM
|
(MAGMA) [ p: p in [ NthPrime(k): k in [1..650] ] | IsPrime(&+[ c: c in [p+1..NextPrime(NextPrime(p))-1] ] - NextPrime(p)) ]; /* Klaus Brockhaus, Mar 29 2007 */
|
|
CROSSREFS
|
Sequence in context: A142789 A158491 A139941 this_sequence A053665 A050522 A071633
Adjacent sequences: A127267 A127268 A127269 this_sequence A127271 A127272 A127273
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
J. M. Bergot (thekingfishb(AT)yahoo.ca), Mar 27 2007
|
|
EXTENSIONS
|
Edited and extended by Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Mar 29 2007
|
|
|
Search completed in 0.002 seconds
|
