A348238 - OEIS

A348238

Partial sums of A348236.

1, 4, 9, 17, 29, 44, 60, 78, 101, 128, 156, 185, 218, 256, 296, 337, 381, 429, 480, 533, 589, 648, 709, 773, 841, 912, 984, 1058, 1137, 1220, 1304, 1389, 1478, 1572, 1668, 1765, 1865, 1969, 2076, 2185, 2297, 2412, 2529, 2649, 2773, 2900, 3028, 3158, 3293, 3432, 3572, 3713

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OFFSET

0,2

LINKS

Paolo Xausa, Table of n, a(n) for n = 0..10000

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

FORMULA

From Elmo R. Oliveira, May 13 2026: (Start)

G.f.: (1 + x)^2 * (1 + 2*x^2 + x^3 + 2*x^4 + x^6) / ((-1-x^2) * (-1+x)^3 * (1+x+x^2+x^3+x^4)).

a(n) = 2*a(n-1) - 2*a(n-2) + 2*a(n-3) - a(n-4) + a(n-5) - 2*a(n-6) + 2*a(n-7) - 2*a(n-8) + a(n-9). (End)

MATHEMATICA

LinearRecurrence[{2, -2, 2, -1, 1, -2, 2, -2, 1}, {1, 4, 9, 17, 29, 44, 60, 78, 101}, 100] (* Paolo Xausa, Feb 28 2024 *)