A389607 A bisection of A221075.

12, 24, 192, 360, 2700, 5040, 37632, 70224, 524172, 978120, 7300800, 13623480, 101687052, 189750624, 1416317952, 2642885280, 19726764300, 36810643320, 274758382272, 512706121224, 3826890587532, 7141075053840, 53301709843200, 99462344632560, 742397047217292, 1385331749802024

Offset

1,1

Comments

Scott R. Shannon discovered that his sequence A388967 (which is not well-understood) contains many terms from this sequence. This is only partly explained by the fact that a(2*t)+1 is a square.

Links

Paolo Xausa, Table of n, a(n) for n = 1..1500

Index entries for linear recurrences with constant coefficients, signature (1,14,-14,-1,1).

Mathematica

LinearRecurrence[{1, 14, -14, -1, 1}, {12, 24, 192, 360, 2700}, 30] (* Paolo Xausa, Oct 09 2025 *)

Crossrefs

Cf. A221075, A388967.

Sequence in context: A130163 A002167 A154268 * A058994 A198808 A249134

Adjacent sequences: A389604 A389605 A389606 * A389608 A389609 A389610

Keyword

nonn,easy

Author

N. J. A. Sloane, Oct 09 2025

Extensions

More terms from Paolo Xausa, Oct 09 2025

Status

approved