A372351 Odd bisection of A371094.

21, 21, 341, 45, 117, 69, 341, 93, 213, 117, 5461, 141, 309, 165, 725, 189, 405, 213, 1877, 237, 501, 261, 1109, 285, 597, 309, 5461, 333, 693, 357, 1493, 381, 789, 405, 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

Offset

1,1

Links

Table of n, a(n) for n=1..60.

Formula

a(n) = A371094(2*n-1).

Mathematica

Table[With[{e = IntegerExponent[6*n - 2, 2]}, (6*n - 2)*2^e + (4^e - 1)/3], {n, 100}] (* Paolo Xausa, Apr 29 2024 *)

Prog

(PARI)
A371094(n) = { my(m=1+3*n, e=valuation(m, 2)); ((m*(2^e)) + (((4^e)-1)/3)); };
A372351(n) = A371094(n+n-1);
(Python)
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

Crossrefs

Row 2 of A372282.

Cf. A371094, and array A371100 (gives the same terms, in different order).

Cf. A372290 (the range of this sequence), A372291 (numbers that occur only once), A372292 (more than once), A372293 (odd numbers not occurring here).

Sequence in context: A056485 A056475 A219913 * A219401 A219449 A165842

Adjacent sequences: A372348 A372349 A372350 * A372352 A372353 A372354

Keyword

nonn

Author

Antti Karttunen, Apr 28 2024

Status

approved