A102608 Numbers L such that 1LM1 is prime and M=L+1.

2, 4, 11, 22, 25, 26, 28, 31, 32, 40, 44, 47, 52, 58, 70, 73, 79, 80, 86, 88, 89, 92, 1009, 1010, 1013, 1016, 1045, 1051, 1070, 1079, 1081, 1088, 1090, 1097, 1111, 1135, 1139, 1142, 1144, 1154, 1162, 1168, 1178, 1190, 1192, 1213, 1228, 1234, 1280, 1283, 1286

Offset

1,1

Links

Table of n, a(n) for n=1..51.

Example

If L=2, then M=3 and 1231 is prime.
If L=40, then M=41 and 140411 is prime.
If L=88, then M=89 and 188891 is prime.

Mathematica

Select[Range[1300], PrimeQ[FromDigits[Flatten[IntegerDigits /@ {1, #, # + 1, 1}]]] &]

Crossrefs

Cf. A102606, A102607.

Sequence in context: A126972 A295947 A018774 * A356648 A290439 A018259

Adjacent sequences: A102605 A102606 A102607 * A102609 A102610 A102611

Keyword

nonn,base

Author

Parthasarathy Nambi, Jan 29 2005

Extensions

Extended by Ray Chandler, Jan 30 2005

Status

approved