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A084836 Palindromic primes with nondecreasing digits up to the middle and then nonincreasing. 3

%I #11 Jun 27 2022 01:51:39

%S 2,3,5,7,11,131,151,181,191,353,373,383,787,797,11311,11411,12421,

%T 12721,12821,13331,13831,13931,14741,15551,16661,17971,19991,33533,

%U 34543,34843,35753,77977,78887,79997,1114111,1117111,1123211,1126211,1129211,1134311

%N Palindromic primes with nondecreasing digits up to the middle and then nonincreasing.

%H Michael S. Branicky, <a href="/A084836/b084836.txt">Table of n, a(n) for n = 1..10000</a>

%H Patrick De Geest, <a href="http://www.worldofnumbers.com/palpri.htm">World of Palindromic Primes</a>

%o (Python)

%o from sympy import isprime

%o from itertools import count, islice, combinations_with_replacement as mc

%o def agen():

%o yield from (2, 3, 5, 7, 11)

%o for d in count(2):

%o ndni = (int("".join(m+m[:-1][::-1])) for m in mc("123456789", d))

%o yield from filter(isprime, ndni)

%o print(list(islice(agen(), 40))) # _Michael S. Branicky_, Jun 26 2022

%Y Cf. A084837, A062351, A062352.

%K nonn,base

%O 1,1

%A _Patrick De Geest_, Jun 07 2003

%E a(39) and beyond from _Michael S. Branicky_, Jun 26 2022

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