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 A074629 #32 Jun 01 2025 23:59:03 %S A074629 2,8,18,32,49,50,72,98,128,162,169,196,200,242,288,338,361,392,441, %T A074629 450,512,578,648,676,722,784,800,882,961,968,1058,1152,1225,1250,1352, %U A074629 1369,1444,1458,1521,1568,1682,1764,1800,1849,1922,2048,2178,2312,2450,2592 %N A074629 Duplicate of A067051. %C A074629 Square terms are in A074216. Nonsquare terms appear to be A001105 except {0}. - _Michel Marcus_, Dec 26 2013 %C A074629 In the prime factorization of n, no odd prime has odd exponent, and 2 has odd exponent or at least one prime == 1 (mod 6) has exponent == 2 (mod 6). - _Robert Israel_, Dec 11 2015 %H A074629 Robert Israel, <a href="/A074629/b074629.txt">Table of n, a(n) for n = 1..10000</a> %F A074629 A000203(n) mod 6 = 3. %F A074629 {n: A084301(n) = 3 }. - _R. J. Mathar_, May 19 2020 %e A074629 n=32: sigma(32) = 63 = 6*10 + 3. %p A074629 select(t -> numtheory:-sigma(t) mod 6 = 3, [$1..10000]); # _Robert Israel_, Dec 11 2015 %t A074629 Select[Range@ 2600, Mod[DivisorSigma[1, #], 6] == 3 &] (* _Michael De Vlieger_, Dec 10 2015 *) %o A074629 (PARI) isok(n) = (sigma(n) % 6) == 3; \\ _Michel Marcus_, Dec 26 2013 %o A074629 (Magma) [n: n in [1..3*10^3] | (SumOfDivisors(n) mod 6) eq 3]; // _Vincenzo Librandi_, Dec 11 2015 %Y A074629 Cf. A000203, A072862, A074384, A074627, A074628, A074630. %Y A074629 Appears to be the same sequence as A067051. - _Ralf Stephan_, Aug 18 2004 %K A074629 dead %O A074629 1,1 %A A074629 _Labos Elemer_, Aug 26 2002