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A109305 Primes containing as substring the string reversal of their index. 1
17, 491, 1823, 6883, 183661, 757063, 9642461, 10398683, 11948737, 61241363, 125644177, 141037697, 168598249, 329147719, 1507060573, 2936125141, 24257906011, 74038127803, 863209344623, 1167992076341 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(21) > 2*10^12. [From Donovan Johnson, May 08 2010]

LINKS

Table of n, a(n) for n=1..20.

EXAMPLE

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.

MATHEMATICA

fQ[n_] := StringPosition[ ToString[ Prime[n]], StringReverse[ ToString[n]]] != {}; Do[ If[ fQ[n], Print[ Prime[n]]], {n, 10^8}] (* Robert G. Wilson v, Jun 28 2005 *)

CROSSREFS

Corresponding indices form A109304.

Sequence in context: A166116 A173148 A142368 * A130660 A185659 A012792

Adjacent sequences: A109302 A109303 A109304 * A109306 A109307 A109308

KEYWORD

base,nonn

AUTHOR

Zak Seidov, Jun 25 2005

EXTENSIONS

a(14)-a(16) from Robert G. Wilson v, Jun 28 2005

a(17)-a(20) from Donovan Johnson, May 08 2010

STATUS

approved

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Last modified March 29 09:02 EDT 2023. Contains 361598 sequences. (Running on oeis4.)