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 A354198 #11 May 24 2022 16:31:48
%S A354198 1,3,1,3,3,3,2,26,23,3,3,3,1,3,21,6,3,9,14,22,2,2,7,182,3,14,313,201,
%T A354198 3,3,3,603,3,3,3,115,3,3,2,3,3,21,2,9,9,3,2,75,2,22,3,109,3,21,46,109,
%U A354198 2,23,7,154,3,6,22,222,2,14,2,22,29,6,1,78,3,161,69,1407,6,2,21,44,7,21,14,201,21,39,3,529
%N A354198 a(n) = A064989(A064989(sigma(sigma(sigma(A003961(A003961(n))))))), where A003961 shifts the prime factorization of n one step towards larger primes, and A064989 shifts it back towards smaller primes.
%C A354198 For any hypothetical odd perfect number opn that is not a multiple of 3, it holds that a(n) = A354196(n) = A348750(n) = n, where n = A064989(A064989(opn)). See also comments in A353365.
%H A354198 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>
%H A354198 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F A354198 a(n) = A064989(A354197(A003961(n))) = A064989(A064989(A066971(A003961(A003961(n))))).
%o A354198 (PARI)
%o A354198 A003961(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
%o A354198 A064989(n) = { my(f=factor(n>>valuation(n, 2))); for(i=1, #f~, f[i, 1] = precprime(f[i, 1]-1)); factorback(f); };
%o A354198 A354198(n) = A064989(A064989(sigma(sigma(sigma(A003961(A003961(n)))))));
%Y A354198 Cf. A000203, A003961, A064989, A066971, A326042, A353365, A354197.
%Y A354198 Cf. also A348750, A354196.
%K A354198 nonn
%O A354198 1,2
%A A354198 _Antti Karttunen_, May 24 2022