A085376 Ratio-dependent insertion sequence I(0.36704) (see the link below).

1, 3, 11, 30, 109, 297, 1079, 2940, 10681, 29103, 105731, 288090, 1046629, 2851797, 10360559, 28229880, 102558961, 279447003, 1015229051, 2766240150, 10049731549, 27382954497, 99482086439, 271063304820, 984771132841

Offset

1,2

Comments

This sequence is the ratio-determined insertion sequence (RDIS) "twin" of I(0.37802)=A080874 and "child" of I(0.33344)=A001835 and I(0.38208)=A001906 in the RDIS recurrence tree (see the link for an explanation of terms). See A082630, A082981, A085348 and A085349 for recent examples of RDIS sequences.

Conjecture: partial sums of A129445. - Sean A. Irvine, Jul 14 2022

Links

Table of n, a(n) for n=1..25.

John W. Layman, Ratio-Determined Insertion Sequences and the Tree of their Recurrence Types, June 2003 [Broken link]

John W. Layman, Ratio-Determined Insertion Sequences and the Tree of their Recurrence Types, June 2003 [local copy, corrected]

John W. Layman, Sequences Generated by Age-Determined Insertion Trees, Jan 2006

John W. Layman, Sequences Generated by Age-Determined Insertion Trees, Jan 2006 [Local copy]

Formula

It is conjectured that a(n) = 10*a(n-2) - a(n-4).

Apparently a(n)*a(n+3) = -3 + a(n+1)*a(n+2). - Ralf Stephan, May 29 2004

Crossrefs

Cf. A001835, A001906, A080874, A082630, A082981, A085348, A085349.

Sequence in context: A346848 A372480 A330148 * A196233 A009131 A003554

Adjacent sequences: A085373 A085374 A085375 * A085377 A085378 A085379

Keyword

nonn

Author

John W. Layman, Jun 26 2003

Status

approved