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 A077798 Palindromic wing primes (a.k.a. near-repdigit palindromic primes) of the general form r*(10^d - 1)/9 + (m-r)*10^floor(d/2) where d is the number of digits (an odd number > 1), r is the repeated digit, and m (different from r) is the middle digit. 48
 101, 131, 151, 181, 191, 313, 353, 373, 383, 727, 757, 787, 797, 919, 929, 11311, 11411, 33533, 77377, 77477, 77977, 1114111, 1117111, 3331333, 3337333, 7772777, 7774777, 7778777, 111181111, 111191111, 777767777, 77777677777, 99999199999, 1111118111111 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Prime versus probable prime status and proofs are given in the author's table. REFERENCES C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 1996-97, pp. 1-9. LINKS Jon E. Schoenfield, Table of n, a(n) for n = 1..124 Patrick De Geest, PWP Reference Table Ernest G. Hibbs, Component Interactions of the Prime Numbers, Ph. D. Thesis, Capitol Technology Univ. (2022), see p. 33. PROG (Magma) a:=[]; for d in [3..13 by 2] do for r in [1..9] do for m in [0..9] do if m ne r then t:=r*((10^d-1) div 9) + (m-r)*10^(d div 2); if IsPrime(t) then a[#a+1]:=t; end if; end if; end for; end for; end for; a; // Jon E. Schoenfield, Nov 04 2018 CROSSREFS Cf. A077775-A077797. Sequence in context: A052086 A154270 A056730 * A089360 A056728 A085112 Adjacent sequences: A077795 A077796 A077797 * A077799 A077800 A077801 KEYWORD nonn,base AUTHOR Patrick De Geest, Nov 16 2002 EXTENSIONS Offset corrected by Arkadiusz Wesolowski, Sep 13 2011 Name edited and one more term added by Jon E. Schoenfield, Nov 03 2018 STATUS approved

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Last modified June 5 22:25 EDT 2023. Contains 363138 sequences. (Running on oeis4.)