cp's OEIS Frontend

A372351 Odd bisection of A371094.

%I A372351 #13 Apr 29 2024 15:45:19
%S A372351 21,21,341,45,117,69,341,93,213,117,5461,141,309,165,725,189,405,213,
%T A372351 1877,237,501,261,1109,285,597,309,5461,333,693,357,1493,381,789,405,
%U A372351 3413,429,885,453,1877,477,981,501,87381,525,1077,549,2261,573,1173,597,4949,621,1269,645,2645,669,1365,693,11605,717
%N A372351 Odd bisection of A371094.
%F A372351 a(n) = A371094(2*n-1).
%t A372351 Table[With[{e = IntegerExponent[6*n - 2, 2]}, (6*n - 2)*2^e + (4^e - 1)/3], {n, 100}] (* _Paolo Xausa_, Apr 29 2024 *)
%o A372351 (PARI)
%o A372351 A371094(n) = { my(m=1+3*n, e=valuation(m,2)); ((m*(2^e)) + (((4^e)-1)/3)); };
%o A372351 A372351(n) = A371094(n+n-1);
%o A372351 (Python)
%o A372351 def A372351(n): return ((m:=6*n-2)<<(e:=(~m & m-1).bit_length()))+((1<<(e<<1))-1)//3 # _Chai Wah Wu_, Apr 28 2024
%Y A372351 Row 2 of A372282.
%Y A372351 Cf. A371094, and array A371100 (gives the same terms, in different order).
%Y A372351 Cf. A372290 (the range of this sequence), A372291 (numbers that occur only once), A372292 (more than once), A372293 (odd numbers not occurring here).
%K A372351 nonn
%O A372351 1,1
%A A372351 _Antti Karttunen_, Apr 28 2024