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 A174884 Palindromic primes using only (decimal) square digits 0,1,4,9. 2
 11, 101, 191, 919, 11411, 19991, 91019, 94049, 94949, 1114111, 1190911, 1409041, 1411141, 1444441, 1490941, 1909091, 1941491, 9049409, 9091909, 9109019, 9110119, 9149419, 9199919, 9400049, 9414149, 9419149, 9440449, 9919199 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Four decimal square digits: 0 = 0^2, 1 = 1^2, 4 = 2^2, 9 = 3^2 With the exception of 11 all palindromic primes have an odd number of digits REFERENCES Roland Sprague, Unterhaltsame Mathematik, neue Probleme, ueberraschende Loesungen, Vieweg, Braunschweig, 1961 David Wells, The Penguin Dictionary of Curious and Interesting Numbers, Penguin Books: London, 1986 LINKS Chai Wah Wu, Table of n, a(n) for n = 1..10000 EXAMPLE 11 = prime(5) = palprime(5), 1st term of sequence. 101 = prime(26) = palprime(6), 2nd term of sequence. Next term using only 0 and 1 is 100111001 = prime(5767473) = palprime(785). MATHEMATICA Select[FromDigits/@Tuples[{0, 1, 4, 9}, 7], PalindromeQ[#]&&PrimeQ[#]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 06 2019 *) CROSSREFS Cf. A002385, A007500, A083185, A155214. Sequence in context: A180404 A142317 A180406 * A121402 A156307 A057532 Adjacent sequences:  A174881 A174882 A174883 * A174885 A174886 A174887 KEYWORD base,nonn AUTHOR Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Apr 01 2010 STATUS approved

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Last modified December 3 16:20 EST 2020. Contains 338906 sequences. (Running on oeis4.)