A047076 a(n+1) is the smallest palindromic prime containing exactly 2 more digits on each end than the previous term, with a(n) as a central substring.

2, 30203, 133020331, 1713302033171, 12171330203317121, 151217133020331712151, 1815121713302033171215181, 16181512171330203317121518161, 331618151217133020331712151816133, 9333161815121713302033171215181613339, 11933316181512171330203317121518161333911

Offset: 1

Author

G. L. Honaker, Jr., Jan 26 2000

Keywords

• base
• fini
• full
• nice
• nonn

References

• Pickover, Clifford A., A Passion for Mathematics: Numbers, Puzzles, Madness, Religion and the Quest for Reality, John Wiley & Sons, Inc., Hoboken, New Jersey (2005) p. 108.

Links

• C. K. Caldwell, Palindromic Primes

Crossrefs

Cf. A053600.

Programs

Mathematica

cc=If[EvenQ[First[#]],Reverse[#],#]&/@Tuples[{Range[0,9],Range[1,9,2]}]; nxt[n_]:=First[Select[Sort[FromDigits[Flatten[Join[{#,IntegerDigits[ n], Reverse[#]}]]]&/@cc],PrimeQ]]; NestList[nxt,2,10] (* Harvey P. Dale, Dec 24 2012 *)