Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #15 Mar 25 2019 14:02:16
%S 11411,14341,1464641,1447441,1444441,144404441,14244444241,
%T 34444344443,74444444447,1444447444441,3444444444443,144444454444441,
%U 14144444444444141,34444444044444443,1414444444444444141,1444444447444444441,104444444444444444401
%N Smallest palindromic prime containing exactly n 4's.
%H Chai Wah Wu, <a href="/A083975/b083975.txt">Table of n, a(n) for n = 1..500</a>
%t Table[d = 4; i = 1;
%t While[ x = IntegerDigits[Prime[i]];
%t x != Reverse[x] || Count[x, d] != n , i++];
%t FromDigits[x], {n, 1, 6}] (* _Robert Price_, Mar 25 2019 *)
%Y Cf. A083972, A083973, A083975, A083976, A083977, A083978, A083979, A083980, A083981.
%K base,nonn
%O 1,1
%A _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), May 21 2003
%E More terms from _Ray G. Opao_, Sep 20 2004
%E Corrected and extended by _Giovanni Resta_, Feb 08 2006