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A230046 Palindromic primes with nondecreasing sum of digits. 1

%I

%S 2,3,5,7,151,181,191,353,373,383,727,757,787,797,17971,19891,19991,

%T 38783,74747,75557,76367,76667,77477,77977,78787,78887,79697,79997,

%U 1879781,1895981,1969691,1987891,1988891,1998991,3799973,3899983,3997993,3998993,7696967

%N Palindromic primes with nondecreasing sum of digits.

%C a(1) = 2; a(n+1) is the smallest palindromic prime with sum of digits >= sum of digits of a(n).

%H Shyam Sunder Gupta, <a href="/A230046/b230046.txt">Table of n, a(n) for n = 1..157</a>

%t a = {}; t = 0; Do[z = n*10^(IntegerLength[n] - 1) + FromDigits@Rest@Reverse@IntegerDigits[n]; If[PrimeQ[z], s = Apply[Plus, IntegerDigits[z]]; If[s >= t, t = s; AppendTo[a, z]]], {n, 10^5}]; a

%Y Cf. A002385, A067954.

%K nonn,base

%O 1,1

%A _Shyam Sunder Gupta_, Oct 06 2013

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Last modified January 19 11:42 EST 2022. Contains 350465 sequences. (Running on oeis4.)