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 A320860 #27 Sep 08 2022 08:46:23 %S A320860 4,4096,4194304,4294967296,4398046511104,4503599627370496, %T A320860 4611686018427387904,4722366482869645213696,4835703278458516698824704, %U A320860 4951760157141521099596496896,40564819207303340847894502572032,41538374868278621028243970633760768 %N A320860 Powers of 2 with initial digit 4. %C A320860 Differs from A067482 first at n = 11. %H A320860 Muniru A Asiru, <a href="/A320860/b320860.txt">Table of n, a(n) for n = 1..320</a> %H A320860 <a href="/index/Di#divseq">Index to divisibility sequences</a> %p A320860 select(x->"4"=""||x[1],[2^n$n=0..150])[]; %t A320860 Select[2^Range[160], First[IntegerDigits[#]] == 4 &] (* _G. C. Greubel_, Oct 27 2018 *) %o A320860 (GAP) Filtered(List([0..150],n->2^n),i->ListOfDigits(i)[1]=4); %o A320860 (PARI) select(x->(digits(x)[1]==4), vector(200, n, 2^n)) \\ _Michel Marcus_, Oct 26 2018 %o A320860 (Magma) [2^n: n in [1..160] | Intseq(2^n)[#Intseq(2^n)] eq 4]; // _G. C. Greubel_, Oct 27 2018 %Y A320860 Cf. A000079 (Powers of 2), A008952 (leading digit of 2^n), A217397 (numbers starting with 4). %Y A320860 Powers of 2 with initial digit k, (k = 1..4): A067488, A067480, A320859, this sequence. %K A320860 base,nonn %O A320860 1,1 %A A320860 _Muniru A Asiru_, Oct 22 2018