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 A053140 #13 Jun 20 2025 10:47:07 %S A053140 181,241,251,257,263,367,373,379,383,389,397,401,409,419,421,431,433, %T A053140 439,443,449,457,461,463,467,479,487,491,499,503,509,521,523,541,547, %U A053140 557,563,569,571,577,587,593,599,601,607,613,617,619,631,641,643,647,653 %N A053140 Odd primes that are not highly-imperfect numbers. %C A053140 The sequence of highly-imperfect numbers begins with 1 and the odd primes up to 113... then even numbers appear and some odd primes are left out. %H A053140 Robert Israel, <a href="/A053140/b053140.txt">Table of n, a(n) for n = 1..10000</a> %p A053140 R:= NULL: count:= 0: m:= 0: q:= 1: %p A053140 for k from 1 do %p A053140 v:= abs(numtheory:-sigma(k)-2*k); %p A053140 if v > m then %p A053140 m:= v; %p A053140 V:= select(isprime,[seq(i,i=q .. k-1,2)]); %p A053140 count:= count + nops(V); %p A053140 R:= R, op(V); %p A053140 q:= k + 1 + (k mod 2); %p A053140 if count > 100 then break fi %p A053140 fi %p A053140 od: %p A053140 R; # _Robert Israel_, Jun 19 2025 %Y A053140 Cf. A074918. %K A053140 nonn %O A053140 1,1 %A A053140 _Joseph L. Pe_, Oct 03 2002 %E A053140 More terms from _Sean A. Irvine_, Dec 11 2021