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 A282183 Numbers k such that the reverse of the first k digits in the decimal expansion of Pi forms a prime. 0
 1, 2, 5, 6, 7, 11, 15, 712, 7599, 13280 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The initial digits of a few corresponding primes are in A007523. The last one a(10)=768556......62951413 is a prime with 13280-digit. That is A092845(13279). LINKS EXAMPLE 1 is a term as the first digit of pi, 3, reversed is prime. 2 is a term as the first two digits of pi, 31, reversed is prime. 3 is not a term as the first three digits of pi, 314, reversed, is not prime. - David A. Corneth, Feb 13 2017 MATHEMATICA Do[If[PrimeQ[FromDigits[Reverse[IntegerDigits[Floor[Pi*10^(n - 1)]]]]], Print[n]], {n, 13335}] Module[{pid=RealDigits[Pi, 10, 20000][[1]]}, Select[Range[16000], PrimeQ[ FromDigits[ Reverse[Take[pid, #]]]]&]] (* Harvey P. Dale, Sep 06 2019 *) CROSSREFS Cf. A092845, A007523, A011545. Sequence in context: A043329 A023699 A058605 * A103025 A134080 A342792 Adjacent sequences:  A282180 A282181 A282182 * A282184 A282185 A282186 KEYWORD nonn,more,base,less AUTHOR XU Pingya, Feb 13 2017 STATUS approved

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Last modified August 12 13:34 EDT 2022. Contains 356077 sequences. (Running on oeis4.)