|
Search: id:A078626
|
|
|
| A078626 |
|
Primes p which concatenated with p+2 give a prime. |
|
+0
1
|
|
| 7, 37, 61, 109, 151, 181, 211, 271, 277, 331, 337, 367, 421, 439, 457, 487, 541, 619, 661, 691, 727, 751, 829, 859, 877, 907, 1039, 1087, 1129, 1201, 1237, 1279, 1321, 1399, 1489, 1549, 1609, 1621, 1699, 1741, 1777, 1831, 1999, 2341, 2347, 2767, 2851
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
EXAMPLE
|
37 is a prime which, concatenated with 37+2=39, gives 3739, a prime; so 37 belongs to the sequence.
|
|
MATHEMATICA
|
a = {}; For[i = 1, i <= 10^3, i++, p = Prime[i]; If[PrimeQ[ToExpression[ToString[p] <> ToString[p + 2]]], a = Append[a, p]]]; a
|
|
CROSSREFS
|
Sequence in context: A077720 A127313 A003521 this_sequence A093342 A093389 A086110
Adjacent sequences: A078623 A078624 A078625 this_sequence A078627 A078628 A078629
|
|
KEYWORD
|
base,easy,nonn
|
|
AUTHOR
|
Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Dec 11 2002
|
|
|
Search completed in 0.002 seconds
|
