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A109304
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Numbers n such that string reversal of n is a substring of n-th prime.
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3
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7, 94, 281, 886, 16638, 60757, 642469, 689301, 784911, 3631421, 7144652, 7967301, 9428958, 17741923, 75060705, 141521639, 1060975242, 3087218304, 32644390236, 43670299761
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OFFSET
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1,1
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COMMENTS
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a(21) > pi(2*10^12). [From Donovan Johnson, May 08 2010]
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LINKS
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Table of n, a(n) for n=1..20.
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EXAMPLE
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94th prime, 491, contains 49 = the string reversal of its index;
281st prime, 1823, contains 182 = the string reversal of its index;
7144652nd prime, 125644177, contains 2564417 = the string reversal of its index; etc.
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MATHEMATICA
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fQ[n_] := StringPosition[ ToString[ Prime[n]], StringReverse[ ToString[n]]] != {}; Do[ If[ fQ[n], Print[n]], {n, 107350907, 2 10^9}] (* Robert G. Wilson v, Jun 28 2005 *)
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CROSSREFS
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Corresponding primes form A109305.
Sequence in context: A218835 A219417 A220405 * A134113 A071584 A132114
Adjacent sequences: A109301 A109302 A109303 * A109305 A109306 A109307
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KEYWORD
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base,nonn
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AUTHOR
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Zak Seidov, Jun 25 2005
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EXTENSIONS
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a(14)-a(16) from Robert G. Wilson v, Jun 28 2005
a(17)-a(20) from Donovan Johnson, May 08 2010
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STATUS
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approved
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