cp's OEIS Frontend

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.

A175730 Numbers with deficiency of 42.

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%I A175730 #28 Jan 22 2021 10:06:32
%S A175730 43,69,99,165,1168,1365,2139136,32062485,33722368,132701205,8592621568
%N A175730 Numbers with deficiency of 42.
%C A175730 Numbers with an abundance of -42.
%C A175730 7454198513685 is also in the sequence. - _Alexander Violette_, Jan 10 2021
%C A175730 Numbers of the form 2^k * (2^(k + 1) + 41) are in the sequence if and only if 2^(k + 1) + 41 is prime. - _David A. Corneth_, Jan 15 2021
%o A175730 (PARI) for(n=1, 100000000, if(((sigma(n)-2*n)==-42), print1(n, ", ")))
%o A175730 (PARI) is(n)=2*n-sigma(n)==42 \\ _Charles R Greathouse IV_, Jan 11 2021
%o A175730 (PARI) list(lim)=my(v=List()); forfactored(n=1,lim\1, if(2*n[1]-sigma(n)==42, listput(v,n[1]))); Vec(v) \\ _Charles R Greathouse IV_, Jan 11 2021
%Y A175730 Cf. A033879 (deficiency).
%K A175730 nonn,more
%O A175730 1,1
%A A175730 _Jason G. Wurtzel_, Aug 24 2010
%E A175730 a(10) from _Alexander Violette_, Jan 10 2021
%E A175730 a(11) from _Charles R Greathouse IV_, Jan 15 2021