This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A101896 #20 May 04 2019 09:26:49 %S A101896 2,61,23,821,4201,270131,61277761,274359834731,23888027348153, %T A101896 86936981079782063,4243031147170261950811,272838646828154727511151, %U A101896 821882010875193363312928672952261,274562423560500997742392394025368175422471,4266472836315949449695828501889595072967427241 %N A101896 Primes obtained if 2^j for some suitable j is written backward. %C A101896 The relevant exponents are collected in A057708. %C A101896 a(23), reverse(2^3489), has 1023 decimal digits. - _Michael De Vlieger_, Dec 03 2015 %H A101896 Michael De Vlieger, <a href="/A101896/b101896.txt">Table of n, a(n) for n = 1..22</a> %F A101896 a(n) = reverse(2^A057708(n)). %e A101896 Reverse 128, obtain 821, a prime. %t A101896 Select[FromDigits@ Reverse@ IntegerDigits[2^#] & /@ Range@ 3200, PrimeQ] (* _Michael De Vlieger_, Dec 03 2015 *) %o A101896 (GAP) a:=Filtered(List(List([1..300],j->Reversed(ListOfDigits(2^j))),k->Sum([1..Size(k)],i->k[i]*10^(Size(k)-i))),IsPrime);; Print(a); # _Muniru A Asiru_, Dec 25 2018 %Y A101896 Cf. A057708. %K A101896 base,nonn %O A101896 1,1 %A A101896 _Labos Elemer_, Jan 28 2005