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 #10 Jul 22 2020 11:39:24
%S 1,2,1,15,25,13,1,65,20,100,38,54,8,48,40,41,9,83,152,19,52,6,16,66,4,
%T 4,69,25,28,7,97,174,4,48,127,11,40,58,48,69,45,40,34,119,6,7,92,61,2,
%U 40,138,105,332,28,70,322,62,231,78,339,245,66,49,439,298
%N Position of the first n-digit prime occurring in the decimal expansion of e.
%C Leading zeros are not allowed.
%H Harvey P. Dale, <a href="/A272304/b272304.txt">Table of n, a(n) for n = 1..200</a>
%e a(1) = 1 because the initial digit "2" of e is prime.
%t With[{ed = RealDigits[E, 10, 10000][[1]]}, Table[Position[Partition[ed, n, 1], _?(PrimeQ[FromDigits[#]] && #[[1]] != 0 &), {1}, 1, Heads -> False], {n, 100}]] // Flatten
%Y Cf. A001113, A198344.
%K nonn,base
%O 1,2
%A _Harvey P. Dale_, Apr 25 2016