A073676 Rearrangement of odd numbers not divisible by 5 such that every right concatenation of terms is a prime.

3, 1, 7, 21, 23, 19, 33, 9, 39, 27, 59, 43, 51, 47, 117, 61, 287, 97, 129, 83, 49, 17, 171, 157, 107, 91, 29, 109, 191, 397, 221, 103, 63, 99, 123, 321, 149, 207, 393, 699, 133, 539, 93, 387, 309, 273, 79, 1121, 249, 457, 243, 213, 137, 643, 443, 693, 67, 1023, 381, 623, 939, 169, 663, 89, 153, 679, 227, 1027

Offset: 1

Author

Amarnath Murthy, Aug 11 2002

Keywords

• base
• nonn

Comments

The number 11 finally appears as a(201).

Examples

			3,31,3119,311951,31195117 are all prime.
		

Programs

Mathematica

used={3}; num=3; Do[n=1; d=IntegerDigits[num]; While[MemberQ[used,n] || !PrimeQ[newNum=FromDigits[Join[d,IntegerDigits[n]]]], n=n+2]; AppendTo[used,n]; num=newNum, {50}]; used

Extensions

Corrected and extended by T. D. Noe, Jan 25 2011