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A002385 Palindromic primes: prime numbers whose decimal expansion is a palindrome.
(Formerly M0670 N0247)
+0
104
2, 3, 5, 7, 11, 101, 131, 151, 181, 191, 313, 353, 373, 383, 727, 757, 787, 797, 919, 929, 10301, 10501, 10601, 11311, 11411, 12421, 12721, 12821, 13331, 13831, 13931, 14341, 14741, 15451, 15551, 16061, 16361, 16561, 16661, 17471, 17971, 18181 (list; graph; listen)
OFFSET

1,1

COMMENT

Every palindrome with an even number of digits is divisible by 11, so 11 is the only member of the sequence with an even number of digits. - David Wasserman (wasserma(AT)spawar.navy.mil), Sep 09 2004

REFERENCES

A. H. Beiler, Recreations in the Theory of Numbers, Dover, NY, 1964, p. 228.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Attila Olah, Table of n, a(n) for n=1..100197

K. S. Brown, On General Palindromic Numbers

P. De Geest, World!Of Palindromic Primes

I. Peterson, Math Trek, Palindromic Primes

M. Shafer, First 401066 Palprimes [Broken link]

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Eric Weisstein's World of Mathematics, Integer Sequence Primes

Wikipedia, Palindromic prime

MAPLE

ff := proc(n) local i, j, k, s, aa, nn, bb, flag; s := n; aa := convert(s, string); nn := length(aa); bb := ``; for i from nn by -1 to 1 do bb := cat(bb, substring(aa, i..i)); od; flag := 0; for j from 1 to nn do if substring(aa, j..j)<>substring(bb, j..j) then flag := 1 fi; od; RETURN(flag); end; gg := proc(i) if ff(ithprime(i)) = 0 then RETURN(ithprime(i)) fi end;

rev:=proc(n) local nn, nnn: nn:=convert(n, base, 10): add(nn[nops(nn)+1-j]*10^(j-1), j=1..nops(nn)) end: a:=proc(n) if n=rev(n) and isprime(n)=true then n else fi end: seq(a(n), n=1..20000); # rev is a Maple program to revert a number - Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 25 2007

MATHEMATICA

Select[ Prime[ Range[ 2100 ] ], IntegerDigits[ # ] == Reverse[ IntegerDigits[ # ] ] & ]

CROSSREFS

A007500 = this sequence union A006567.

Cf. A016041, A029732, A117697.

Sequence in context: A052480 A083137 A077652 this_sequence A069217 A083139 A088562

Adjacent sequences: A002382 A002383 A002384 this_sequence A002386 A002387 A002388

KEYWORD

nonn,base,nice,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Simon Plouffe (simon.plouffe(AT)gmail.com)

EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), Oct 25 2000

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Last modified December 2 11:54 EST 2009. Contains 167921 sequences.


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