A144450 Second bisection of A061039.

7, 1, 55, 91, 5, 187, 247, 35, 391, 475, 7, 667, 775, 11, 1015, 1147, 143, 1435, 1591, 65, 1927, 2107, 85, 2491, 2695, 323, 3127, 3355, 133, 3835, 4087, 161, 4615, 4891, 575, 5467, 5767, 75, 6391, 6715, 87, 7387, 7735, 899, 8455, 8827, 341, 9595, 9991, 385, 10807, 11227, 1295, 12091, 12535

Offset

1,1

Comments

Related to the Paschen spectrum of hydrogen. Contains only odd numbers. The sequence read modulo 9 is "full" and contains all numbers from 0 to 8.

Links

G. C. Greubel, Table of n, a(n) for n = 1..5000

Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).

Formula

a(n) = A061039(2*n+2).

a(n) = 3*a(n-27) - 3*a(n-54) + a(n-81). - G. C. Greubel, Mar 06 2022

Mathematica

Numerator[1/9 - 1/(2*Range[2, 100])^2] (* G. C. Greubel, Mar 06 2022 *)

Prog

(Sage) [numerator(1/9 -1/(2*n+2)^2) for n in (1..100)] # G. C. Greubel, Mar 06 2022

Crossrefs

Cf. A061039, A144448.

Sequence in context: A218017 A075502 A052104 * A051339 A134141 A350202

Adjacent sequences: A144447 A144448 A144449 * A144451 A144452 A144453

Keyword

nonn

Author

Paul Curtz, Oct 06 2008

Extensions

Formula index corrected, extended by R. J. Mathar, Dec 02 2008

Status

approved