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 A001749 #52 Feb 19 2024 01:48:03 %S A001749 8,12,20,28,44,52,68,76,92,116,124,148,164,172,188,212,236,244,268, %T A001749 284,292,316,332,356,388,404,412,428,436,452,508,524,548,556,596,604, %U A001749 628,652,668,692,716,724,764,772,788,796,844,892,908,916,932,956,964,1004,1028,1052,1076,1084,1108,1124,1132,1172,1228,1244,1252 %N A001749 Primes multiplied by 4. %C A001749 Numbers k such that Sum_{d|k} (-1)^d = A048272(k) = 2. - _Benoit Cloitre_, Apr 14 2002 %H A001749 Paolo P. Lava, <a href="/A001749/b001749.txt">Table of n, a(n) for n = 1..20000</a> %t A001749 4 * Prime[Range[66]] (* _Vladimir Joseph Stephan Orlovsky_, Apr 29 2008 *) %o A001749 (Haskell) %o A001749 a001749 = (* 4) . a000040 -- _Reinhard Zumkeller_, Feb 20 2012 %o A001749 (PARI) a(n)=4*prime(n) \\ _Charles R Greathouse IV_, Mar 25 2014 %o A001749 (PARI) 4 * primes(66) \\ _Joerg Arndt_, Mar 26 2014 %o A001749 (Magma) [4*p: p in PrimesUpTo(300)]; // _Vincenzo Librandi_, Mar 26 2014 %Y A001749 Cf. A000040, A003415, A048272. %K A001749 nonn,easy %O A001749 1,1 %A A001749 _N. J. A. Sloane_