A152254 Twice A084773.

2, 12, 104, 1008, 10272, 107712, 1150592, 12451584, 136053248, 1497664512, 16583583744, 184511361024, 2061074178048, 23100352413696, 259648659554304, 2925683135152128, 33037383972814848, 373774017998094336, 4235888981636022272, 48076611822491271168

Offset: 0

Author

Eric Bach (bach(AT)cs.wisc.edu), Oct 15 2009

Keywords

• nonn

References

• Andras Kornai, Mathematical Linguistics (Springer-Verlag 2008), p. 36. (Gives a sequence which matches the first five terms.)

Links

• G. C. Greubel, Table of n, a(n) for n = 0..930

Crossrefs

Cf. A000079, A001850, A084773.

Programs

Magma

[2^(n+1)*Evaluate(LegendrePolynomial(n), 3): n in [0..40]]; // G. C. Greubel, May 22 2023

Mathematica

Table[2^(n+1)*LegendreP[n, 3], {n,0,40}] (* G. C. Greubel, May 22 2023 *)

SageMath

[2^(n+1)*gen_legendre_P(n,0,3) for n in range(41)] # G. C. Greubel, May 22 2023

Extensions

Offset changed by Petros Hadjicostas, Feb 09 2021