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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. 6
2, 30203, 133020331, 1713302033171, 12171330203317121, 151217133020331712151, 1815121713302033171215181, 16181512171330203317121518161, 331618151217133020331712151816133, 9333161815121713302033171215181613339, 11933316181512171330203317121518161333911 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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

Table of n, a(n) for n=1..11.

C. K. Caldwell, Palindromic Primes

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 *)

CROSSREFS

Cf. A053600.

Sequence in context: A153912 A247790 A233460 * A176721 A030462 A228556

Adjacent sequences:  A047073 A047074 A047075 * A047077 A047078 A047079

KEYWORD

base,fini,full,nice,nonn

AUTHOR

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

STATUS

approved

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Last modified January 22 22:38 EST 2018. Contains 298093 sequences.