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.

A371533 Numbers k such that A001227(2*k) = A001222(2*k).

This page as a plain text file.
%I A371533 #7 Apr 04 2024 10:36:11
%S A371533 1,3,5,7,9,11,13,17,19,23,25,27,29,30,31,37,41,42,43,47,49,53,59,61,
%T A371533 66,67,70,71,73,78,79,81,83,89,97,101,102,103,107,109,110,113,114,121,
%U A371533 125,127,130,131,137,138,139,149,151,154,157,163,167,169,170,173,174,179,180,181,182,186,190,191,193,197,199
%N A371533 Numbers k such that A001227(2*k) = A001222(2*k).
%t A371533 Select[Range[200], DivisorSigma[0, #/2^IntegerExponent[#, 2]] == PrimeOmega[2*#] &] (* _Amiram Eldar_, Mar 26 2024 *)
%o A371533 (Magma) [k: k in [1..200] | #Divisors(4*k)-#Divisors(2*k) eq
%o A371533 (2*k eq 1 select 0 else &+[p[2]: p in Factorization(2*k)])];
%Y A371533 Cf. A001222, A001227.
%K A371533 nonn
%O A371533 1,2
%A A371533 _Juri-Stepan Gerasimov_, Mar 26 2024