A099749 The number defined by the decimal string "a(2n) 1's followed by a(2n+1)" is prime.

1, 1, 1, 3, 1, 7, 1, 9, 2, 3, 3, 7, 4, 3, 4, 7, 4, 9, 5, 9, 7, 7, 7, 9, 8, 3, 10, 3, 16, 9, 18, 1, 22, 1, 22, 7, 23, 3, 28, 7, 39, 7, 49, 9, 83, 3, 130, 7, 135, 7, 214, 7, 220, 3, 316, 1, 610, 7, 683, 9, 719, 9, 766, 7, 1030, 1, 1313, 3, 1451, 9, 1678, 9, 2152, 7, 2575, 7

Offset

0,4

Links

Table of n, a(n) for n=0..75.

Example

The numbers 11, 13, 17, 19, 113, 1117, 11113, 11117, 11119, 111119, ... are primes.

Crossrefs

Sequence in context: A277934 A063754 A163117 * A210442 A077202 A086665

Adjacent sequences: A099746 A099747 A099748 * A099750 A099751 A099752

Keyword

base,nonn

Author

Pierre CAMI, Nov 10 2004

Extensions

Edited by Don Reble, Nov 07 2005

Status

approved