A371533 - OEIS

%I #7 Apr 04 2024 10:36:11

%S 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 66,67,70,71,73,78,79,81,83,89,97,101,102,103,107,109,110,113,114,121,

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

%t Select[Range[200], DivisorSigma[0, #/2^IntegerExponent[#, 2]] == PrimeOmega[2*#] &] (* _Amiram Eldar_, Mar 26 2024 *)

%o (Magma) [k: k in [1..200] | #Divisors(4*k)-#Divisors(2*k) eq

%o (2*k eq 1 select 0 else &+[p[2]: p in Factorization(2*k)])];

%Y Cf. A001222, A001227.

%K nonn

%O 1,2

%A _Juri-Stepan Gerasimov_, Mar 26 2024