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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.
9
2, 30203, 133020331, 1713302033171, 12171330203317121, 151217133020331712151, 1815121713302033171215181, 16181512171330203317121518161, 331618151217133020331712151816133, 9333161815121713302033171215181613339, 11933316181512171330203317121518161333911
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.
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: A247790 A233460 A324164 * A176721 A030462 A228556
KEYWORD
base,fini,full,nice,nonn
AUTHOR
G. L. Honaker, Jr., Jan 26 2000
STATUS
approved