A349803 a(3*n) = 1 + 4*n^2, a(1+3*n) = 2 + 4*n*(n+1), a(2+3*n) = 5 + 4*n*(n+1).

1, 2, 5, 5, 10, 13, 17, 26, 29, 37, 50, 53, 65, 82, 85, 101, 122, 125, 145, 170, 173, 197, 226, 229, 257, 290, 293, 325, 362, 365, 401, 442, 445, 485, 530, 533, 577, 626, 629, 677, 730, 733, 785, 842, 845, 901, 962

Offset

0,2

Comments

A261327 sorted in nondecreasing order.

Links

Table of n, a(n) for n=0..46.

Index entries for linear recurrences with constant coefficients, signature (1,0,2,-2,0,-1,1).

Formula

a(-n) = a(n) - A099838(n+2).

a(n) = a(n-3) + 4*A004523(n-1) for n >= 3

= a(n-6) + 8*A004396(n-3) for n >= 6

= a(n-9) + 12*A004523(n-4) for n >= 9

= a(n-12) + 16*A004396(n-6) for n >= 12

...

Mathematica

nterms=100; LinearRecurrence[{1, 0, 2, -2, 0, -1, 1}, {1, 2, 5, 5, 10, 13, 17}, nterms] (* Paolo Xausa, Dec 01 2021 *)

Crossrefs

Cf. A261327.

Trisections: A053755, A069894, A078370.

Cf. A004396, A004523, A099838.

Sequence in context: A212624 A351475 A034387 * A081240 A184443 A238655

Adjacent sequences: A349800 A349801 A349802 * A349804 A349805 A349806

Keyword

nonn,easy

Author

Paul Curtz, Dec 01 2021

Status

approved