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 A334105 #21 May 01 2020 12:10:40 %S A334105 127,129,133,139,141,147,161,163,171,173,177,189,191,197,199,201,203, %T A334105 207,209,211,213,215,217,223,229,231,235,237,243,245,247,253,254,258, %U A334105 259,261,263,266,269,271,273,277,278,279,282,285,294,295,297,299,311,315,317,319,321,322,326,327,331,333,335,341,342,345,346,349,351 %N A334105 Numbers m for which A329697(m) = 5. %H A334105 Antti Karttunen, <a href="/A334105/b334105.txt">Table of n, a(n) for n = 1..50071; all terms < 2^31</a> %e A334105 127 = 63*2 + 1 is a term, as 127 is a prime and 63 is in A334104 as A329697(63) = 4. %e A334105 2^32 -1 = 4294967295 = 3*5*17*257*65537 is a term as it is a product of five Fermat primes, thus in five steps all odd primes can be eliminated with p -> (p-1) map. %e A334105 Likewise for 1442840405 = 5 * 17 * 257^3. (The first term with binary weight = 24). %t A334105 Position[Array[Length@ NestWhileList[# - #/FactorInteger[#][[-1, 1]] &, #, # != 2^IntegerExponent[#, 2] &] - 1 &, 360], 5][[All, 1]] (* _Michael De Vlieger_, Apr 30 2020 *) %o A334105 (PARI) %o A334105 A329697(n) = if(!bitand(n,n-1),0,1+A329697(n-(n/vecmax(factor(n)[, 1])))); %o A334105 isA334105(n) = (5==A329697(n)); %Y A334105 Row 5 of A334100. %Y A334105 Cf. A052126, A171462, A209229, A329697, A334101, A334102, A334103, A334104, A334106. %Y A334105 Cf. A334095 (primes present). %K A334105 nonn %O A334105 1,1 %A A334105 _Antti Karttunen_, Apr 14 2020