cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A299284 Partial sums of A299283.

Original entry on oeis.org

1, 8, 30, 78, 162, 292, 478, 731, 1061, 1478, 1992, 2614, 3354, 4222, 5228, 6383, 7697, 9180, 10842, 12694, 14746, 17008, 19490, 22203, 25157, 28362, 31828, 35566, 39586, 43898, 48512, 53439, 58689, 64272, 70198, 76478, 83122, 90140, 97542, 105339, 113541
Offset: 0

Views

Author

N. J. A. Sloane, Feb 10 2018

Keywords

Crossrefs

Cf. A299283.
The 28 uniform 3D tilings: cab: A299266, A299267; crs: A299268, A299269; fcu: A005901, A005902; fee: A299259, A299265; flu-e: A299272, A299273; fst: A299258, A299264; hal: A299274, A299275; hcp: A007899, A007202; hex: A005897, A005898; kag: A299256, A299262; lta: A008137, A299276; pcu: A005899, A001845; pcu-i: A299277, A299278; reo: A299279, A299280; reo-e: A299281, A299282; rho: A008137, A299276; sod: A005893, A005894; sve: A299255, A299261; svh: A299283, A299284; svj: A299254, A299260; svk: A010001, A063489; tca: A299285, A299286; tcd: A299287, A299288; tfs: A005899, A001845; tsi: A299289, A299290; ttw: A299257, A299263; ubt: A299291, A299292; bnn: A007899, A007202. See the Proserpio link in A299266 for overview.

Programs

  • Mathematica
    LinearRecurrence[{3,-3,1,1,-3,3,-1},{1,8,30,78,162,292,478},50] (* Harvey P. Dale, Mar 30 2024 *)
  • PARI
    Vec((1 + 5*x + 9*x^2 + 11*x^3 + 9*x^4 + 5*x^5 + x^6) / ((1 - x)^4*(1 + x)*(1 + x^2)) + O(x^60)) \\ Colin Barker, Feb 11 2018

Formula

From Colin Barker, Feb 11 2018: (Start)
G.f.: (1 + 5*x + 9*x^2 + 11*x^3 + 9*x^4 + 5*x^5 + x^6) / ((1 - x)^4*(1 + x)*(1 + x^2)).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) + a(n-4) - 3*a(n-5) + 3*a(n-6) - a(n-7) for n>6.
(End)

A299285 Coordination sequence for "tea" 3D uniform tiling.

Original entry on oeis.org

1, 10, 33, 73, 128, 199, 285, 388, 506, 640, 789, 955, 1136, 1333, 1545, 1774, 2018, 2278, 2553, 2845, 3152, 3475, 3813, 4168, 4538, 4924, 5325, 5743, 6176, 6625, 7089, 7570, 8066, 8578, 9105, 9649, 10208, 10783, 11373, 11980, 12602, 13240, 13893
Offset: 0

Views

Author

N. J. A. Sloane, Feb 10 2018

Keywords

Comments

First 20 terms computed by Davide M. Proserpio using ToposPro.

Crossrefs

See A299286 for partial sums.
The 28 uniform 3D tilings: cab: A299266, A299267; crs: A299268, A299269; fcu: A005901, A005902; fee: A299259, A299265; flu-e: A299272, A299273; fst: A299258, A299264; hal: A299274, A299275; hcp: A007899, A007202; hex: A005897, A005898; kag: A299256, A299262; lta: A008137, A299276; pcu: A005899, A001845; pcu-i: A299277, A299278; reo: A299279, A299280; reo-e: A299281, A299282; rho: A008137, A299276; sod: A005893, A005894; sve: A299255, A299261; svh: A299283, A299284; svj: A299254, A299260; svk: A010001, A063489; tca: A299285, A299286; tcd: A299287, A299288; tfs: A005899, A001845; tsi: A299289, A299290; ttw: A299257, A299263; ubt: A299291, A299292; bnn: A007899, A007202. See the Proserpio link in A299266 for overview.
Cf. A056594.

Programs

  • Mathematica
    LinearRecurrence[{2,-1,0,1,-2,1},{1,10,33,73,128,199,285},50] (* Harvey P. Dale, May 09 2022 *)
  • PARI
    a(n)=([0,1,0,0,0,0; 0,0,1,0,0,0; 0,0,0,1,0,0; 0,0,0,0,1,0; 0,0,0,0,0,1; 1,-2,1,0,-1,2]^n*[1;10;33;73;128;199])[1,1] \\ Charles R Greathouse IV, Oct 18 2022

Formula

From Colin Barker, Feb 11 2018: (Start)
G.f.: (1 + 8*x + 14*x^2 + 17*x^3 + 14*x^4 + 8*x^5 + x^6) / ((1 - x)^3*(1 + x)*(1 + x^2)).
a(n) = 2*a(n-1) - a(n-2) + a(n-4) - 2*a(n-5) + a(n-6) for n>6. (End)
[I suspect Barker's formulas only conjectures. - N. J. A. Sloane, Jun 12 2024]
If the above formulas are true, then a(n) = (31 - 3*(-1)^n + 126*n^2 + 4*A056594(n))/16 for n > 0. - Stefano Spezia, Jun 08 2024

A299286 Partial sums of A299285.

Original entry on oeis.org

1, 11, 44, 117, 245, 444, 729, 1117, 1623, 2263, 3052, 4007, 5143, 6476, 8021, 9795, 11813, 14091, 16644, 19489, 22641, 26116, 29929, 34097, 38635, 43559, 48884, 54627, 60803, 67428, 74517, 82087, 90153, 98731, 107836, 117485, 127693, 138476, 149849
Offset: 0

Views

Author

N. J. A. Sloane, Feb 10 2018

Keywords

Crossrefs

Cf. A299285.
The 28 uniform 3D tilings: cab: A299266, A299267; crs: A299268, A299269; fcu: A005901, A005902; fee: A299259, A299265; flu-e: A299272, A299273; fst: A299258, A299264; hal: A299274, A299275; hcp: A007899, A007202; hex: A005897, A005898; kag: A299256, A299262; lta: A008137, A299276; pcu: A005899, A001845; pcu-i: A299277, A299278; reo: A299279, A299280; reo-e: A299281, A299282; rho: A008137, A299276; sod: A005893, A005894; sve: A299255, A299261; svh: A299283, A299284; svj: A299254, A299260; svk: A010001, A063489; tca: A299285, A299286; tcd: A299287, A299288; tfs: A005899, A001845; tsi: A299289, A299290; ttw: A299257, A299263; ubt: A299291, A299292; bnn: A007899, A007202. See the Proserpio link in A299266 for overview.

Formula

Conjectures from Colin Barker, Feb 11 2018: (Start)
G.f.: (1 + 8*x + 14*x^2 + 17*x^3 + 14*x^4 + 8*x^5 + x^6) / ((1 - x)^4*(1 + x)*(1 + x^2)).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) + a(n-4) - 3*a(n-5) + 3*a(n-6) - a(n-7) for n>6.
(End)

A299287 Coordination sequence for "tcd" 3D uniform tiling.

Original entry on oeis.org

1, 10, 33, 72, 126, 196, 281, 382, 498, 630, 777, 940, 1118, 1312, 1521, 1746, 1986, 2242, 2513, 2800, 3102, 3420, 3753, 4102, 4466, 4846, 5241, 5652, 6078, 6520, 6977, 7450, 7938, 8442, 8961, 9496, 10046, 10612, 11193, 11790, 12402, 13030, 13673, 14332
Offset: 0

Views

Author

N. J. A. Sloane, Feb 10 2018

Keywords

Comments

First 20 terms computed by Davide M. Proserpio using ToposPro.

Crossrefs

See A299288 for partial sums.
The 28 uniform 3D tilings: cab: A299266, A299267; crs: A299268, A299269; fcu: A005901, A005902; fee: A299259, A299265; flu-e: A299272, A299273; fst: A299258, A299264; hal: A299274, A299275; hcp: A007899, A007202; hex: A005897, A005898; kag: A299256, A299262; lta: A008137, A299276; pcu: A005899, A001845; pcu-i: A299277, A299278; reo: A299279, A299280; reo-e: A299281, A299282; rho: A008137, A299276; sod: A005893, A005894; sve: A299255, A299261; svh: A299283, A299284; svj: A299254, A299260; svk: A010001, A063489; tca: A299285, A299286; tcd: A299287, A299288; tfs: A005899, A001845; tsi: A299289, A299290; ttw: A299257, A299263; ubt: A299291, A299292; bnn: A007899, A007202. See the Proserpio link in A299266 for overview.

Programs

  • Mathematica
    LinearRecurrence[{2, 0, -2, 1}, {1, 10, 33, 72, 126}, 50] (* Paolo Xausa, Aug 28 2024 *)
  • PARI
    Vec((1 + 8*x + 13*x^2 + 8*x^3 + x^4) / ((1 - x)^3*(1 + x)) + O(x^60)) \\ Colin Barker, Feb 11 2018

Formula

G.f.: (x^4 + 8*x^3 + 13*x^2 + 8*x + 1) / ((1 + x)*(1 - x)^3).
From Colin Barker, Feb 11 2018: (Start)
a(n) = (31*n^2 + 8) / 4 for even n>0.
a(n) = (31*n^2 + 9) / 4 for odd n>0.
a(n) = 2*a(n-1) - 2*a(n-3) + a(n-4) for n>4. (End)
E.g.f.: ((8 + 31*x + 31*x^2)*cosh(x) + (9 + 31*x + 31*x^2)*sinh(x) - 4)/4. - Stefano Spezia, Jun 08 2024

A299288 Partial sums of A299287.

Original entry on oeis.org

1, 11, 44, 116, 242, 438, 719, 1101, 1599, 2229, 3006, 3946, 5064, 6376, 7897, 9643, 11629, 13871, 16384, 19184, 22286, 25706, 29459, 33561, 38027, 42873, 48114, 53766, 59844, 66364, 73341, 80791, 88729, 97171, 106132, 115628, 125674, 136286, 147479, 159269
Offset: 0

Views

Author

N. J. A. Sloane, Feb 10 2018

Keywords

Crossrefs

Cf. A299287.
The 28 uniform 3D tilings: cab: A299266, A299267; crs: A299268, A299269; fcu: A005901, A005902; fee: A299259, A299265; flu-e: A299272, A299273; fst: A299258, A299264; hal: A299274, A299275; hcp: A007899, A007202; hex: A005897, A005898; kag: A299256, A299262; lta: A008137, A299276; pcu: A005899, A001845; pcu-i: A299277, A299278; reo: A299279, A299280; reo-e: A299281, A299282; rho: A008137, A299276; sod: A005893, A005894; sve: A299255, A299261; svh: A299283, A299284; svj: A299254, A299260; svk: A010001, A063489; tca: A299285, A299286; tcd: A299287, A299288; tfs: A005899, A001845; tsi: A299289, A299290; ttw: A299257, A299263; ubt: A299291, A299292; bnn: A007899, A007202. See the Proserpio link in A299266 for overview.

Programs

  • PARI
    Vec((1 + 8*x + 13*x^2 + 8*x^3 + x^4) / ((1 - x)^4*(1 + x)) + O(x^60)) \\ Colin Barker, Feb 11 2018

Formula

From Colin Barker, Feb 11 2018: (Start)
G.f.: (1 + 8*x + 13*x^2 + 8*x^3 + x^4) / ((1 - x)^4*(1 + x)).
a(n) = (62*n^3 + 93*n^2 + 82*n + 24) / 24 for n even.
a(n) = (62*n^3 + 93*n^2 + 82*n + 27) / 24 for n odd.
a(n) = 3*a(n-1) - 2*a(n-2) - 2*a(n-3) + 3*a(n-4) - a(n-5) for n>4.
(End)

A299289 Coordination sequence for "tsi" 3D uniform tiling.

Original entry on oeis.org

1, 8, 28, 60, 106, 164, 236, 320, 418, 528, 652, 788, 938, 1100, 1276, 1464, 1666, 1880, 2108, 2348, 2602, 2868, 3148, 3440, 3746, 4064, 4396, 4740, 5098, 5468, 5852, 6248, 6658, 7080, 7516, 7964, 8426, 8900, 9388, 9888, 10402, 10928
Offset: 0

Views

Author

N. J. A. Sloane, Feb 10 2018

Keywords

Comments

First 20 terms computed by Davide M. Proserpio using ToposPro.

References

  • B. Grünbaum, Uniform tilings of 3-space, Geombinatorics, 4 (1994), 49-56. See tiling #12.

Crossrefs

See A299290 for partial sums.
The 28 uniform 3D tilings: cab: A299266, A299267; crs: A299268, A299269; fcu: A005901, A005902; fee: A299259, A299265; flu-e: A299272, A299273; fst: A299258, A299264; hal: A299274, A299275; hcp: A007899, A007202; hex: A005897, A005898; kag: A299256, A299262; lta: A008137, A299276; pcu: A005899, A001845; pcu-i: A299277, A299278; reo: A299279, A299280; reo-e: A299281, A299282; rho: A008137, A299276; sod: A005893, A005894; sve: A299255, A299261; svh: A299283, A299284; svj: A299254, A299260; svk: A010001, A063489; tca: A299285, A299286; tcd: A299287, A299288; tfs: A005899, A001845; tsi: A299289, A299290; ttw: A299257, A299263; ubt: A299291, A299292; bnn: A007899, A007202. See the Proserpio link in A299266 for overview.

Formula

Conjectures from Colin Barker, Feb 11 2018: (Start)
G.f.: (1 + 6*x + 12*x^2 + 6*x^3 + x^4) / ((1 - x)^3*(1 + x)).
a(n) = (13*n^2 + 4) / 2 for n>0 and even.
a(n) = (13*n^2 + 3) / 2 for n odd.
a(n) = 2*a(n-1) - 2*a(n-3) + a(n-4) for n>4. (End)
Conjectured e.g.f.: ((4 + 13*x + 13*x^2)*cosh(x) + (3 + 13*x + 13*x^2)*sinh(x) - 2)/2. - Stefano Spezia, Jun 08 2024

A299290 Partial sums of A299289.

Original entry on oeis.org

1, 9, 37, 97, 203, 367, 603, 923, 1341, 1869, 2521, 3309, 4247, 5347, 6623, 8087, 9753, 11633, 13741, 16089, 18691, 21559, 24707, 28147, 31893, 35957, 40353, 45093, 50191, 55659, 61511, 67759, 74417, 81497, 89013, 96977, 105403, 114303, 123691
Offset: 0

Views

Author

N. J. A. Sloane, Feb 10 2018

Keywords

Crossrefs

Cf. A299289.
The 28 uniform 3D tilings: cab: A299266, A299267; crs: A299268, A299269; fcu: A005901, A005902; fee: A299259, A299265; flu-e: A299272, A299273; fst: A299258, A299264; hal: A299274, A299275; hcp: A007899, A007202; hex: A005897, A005898; kag: A299256, A299262; lta: A008137, A299276; pcu: A005899, A001845; pcu-i: A299277, A299278; reo: A299279, A299280; reo-e: A299281, A299282; rho: A008137, A299276; sod: A005893, A005894; sve: A299255, A299261; svh: A299283, A299284; svj: A299254, A299260; svk: A010001, A063489; tca: A299285, A299286; tcd: A299287, A299288; tfs: A005899, A001845; tsi: A299289, A299290; ttw: A299257, A299263; ubt: A299291, A299292; bnn: A007899, A007202. See the Proserpio link in A299266 for overview.

Formula

Conjectures from Colin Barker, Feb 11 2018: (Start)
G.f.: (1 + 6*x + 12*x^2 + 6*x^3 + x^4) / ((1 - x)^4*(1 + x)).
a(n) = (12 + 34*n + 39*n^2 + 26*n^3) / 12 for n even.
a(n) = (9 + 34*n + 39*n^2 + 26*n^3) / 12 for n odd.
a(n) = 3*a(n-1) - 2*a(n-2) - 2*a(n-3) + 3*a(n-4) - a(n-5) for n>4.
(End)

A299291 Coordination sequence for "ubt" 3D uniform tiling.

Original entry on oeis.org

1, 5, 14, 29, 56, 85, 130, 181, 226, 299, 382, 445, 538, 635, 708, 845, 962, 1079, 1218, 1363, 1456, 1671, 1808, 1987, 2170, 2365, 2470, 2777, 2920, 3169, 3394, 3641, 3750, 4163, 4298, 4625, 4890, 5191, 5296, 5829, 5942, 6355, 6658, 7015, 7108, 7775, 7852, 8359, 8698, 9113, 9186
Offset: 0

Views

Author

N. J. A. Sloane, Feb 10 2018

Keywords

Comments

First 80 terms computed by Davide M. Proserpio using ToposPro.

References

  • B. Grünbaum, Uniform tilings of 3-space, Geombinatorics, 4 (1994), 49-56. See tiling #10.

Crossrefs

See A299292 for partial sums.
The 28 uniform 3D tilings: cab: A299266, A299267; crs: A299268, A299269; fcu: A005901, A005902; fee: A299259, A299265; flu-e: A299272, A299273; fst: A299258, A299264; hal: A299274, A299275; hcp: A007899, A007202; hex: A005897, A005898; kag: A299256, A299262; lta: A008137, A299276; pcu: A005899, A001845; pcu-i: A299277, A299278; reo: A299279, A299280; reo-e: A299281, A299282; rho: A008137, A299276; sod: A005893, A005894; sve: A299255, A299261; svh: A299283, A299284; svj: A299254, A299260; svk: A010001, A063489; tca: A299285, A299286; tcd: A299287, A299288; tfs: A005899, A001845; tsi: A299289, A299290; ttw: A299257, A299263; ubt: A299291, A299292; bnn: A007899, A007202. See the Proserpio link in A299266 for overview.

Programs

  • Mathematica
    LinearRecurrence[{-1,0,1,1,0,2,2,0,-2,-2,0,-1,-1,0,1,1},{1,5,14,29,56,85,130,181,226,299,382,445,538,635,708,845,962,1079,1218,1363,1456},60] (* Harvey P. Dale, Aug 20 2021 *)
  • PARI
    Vec((12*x^20 + 16*x^19 - 20*x^17 - 27*x^16 - 8*x^15 + 3*x^14 + 46*x^13 + 115*x^12 + 176*x^11 + 212*x^10 + 226*x^9 + 228*x^8 + 214*x^7 + 170*x^6 + 122*x^5 + 79*x^4 + 42*x^3 + 19*x^2 + 6*x + 1) / ((1 + x)*(1 - x^3)*(1 - x^6)^2) + O(x^50)) \\ Colin Barker, Feb 14 2018

Formula

G.f.: (12*x^20 + 16*x^19 - 20*x^17 - 27*x^16 - 8*x^15 + 3*x^14 + 46*x^13 + 115*x^12 + 176*x^11 + 212*x^10 + 226*x^9 + 228*x^8 + 214*x^7 + 170*x^6 + 122*x^5 + 79*x^4 + 42*x^3 + 19*x^2 + 6*x + 1) / ((1 + x)*(1 - x^3)*(1 - x^6)^2). - N. J. A. Sloane, Feb 13 2018
a(n) = -a(n-1) + a(n-3) + a(n-4) + 2*a(n-6) + 2*a(n-7) - 2*a(n-9) - 2*a(n-10) - a(n-12) - a(n-13) + a(n-15) + a(n-16) for n>17. - Colin Barker, Feb 14 2018

A299292 Partial sums of A299291.

Original entry on oeis.org

1, 6, 20, 49, 105, 190, 320, 501, 727, 1026, 1408, 1853, 2391, 3026, 3734, 4579, 5541, 6620, 7838, 9201, 10657, 12328, 14136, 16123, 18293, 20658, 23128, 25905, 28825, 31994, 35388, 39029, 42779, 46942, 51240, 55865, 60755, 65946, 71242, 77071, 83013, 89368, 96026
Offset: 0

Views

Author

N. J. A. Sloane, Feb 10 2018

Keywords

Comments

First 80 terms computed by Davide M. Proserpio using ToposPro.

Crossrefs

Cf. A299291.
The 28 uniform 3D tilings: cab: A299266, A299267; crs: A299268, A299269; fcu: A005901, A005902; fee: A299259, A299265; flu-e: A299272, A299273; fst: A299258, A299264; hal: A299274, A299275; hcp: A007899, A007202; hex: A005897, A005898; kag: A299256, A299262; lta: A008137, A299276; pcu: A005899, A001845; pcu-i: A299277, A299278; reo: A299279, A299280; reo-e: A299281, A299282; rho: A008137, A299276; sod: A005893, A005894; sve: A299255, A299261; svh: A299283, A299284; svj: A299254, A299260; svk: A010001, A063489; tca: A299285, A299286; tcd: A299287, A299288; tfs: A005899, A001845; tsi: A299289, A299290; ttw: A299257, A299263; ubt: A299291, A299292; bnn: A007899, A007202. See the Proserpio link in A299266 for overview.

Programs

  • PARI
    Vec((12*x^20 + 16*x^19 - 20*x^17 - 27*x^16 - 8*x^15 + 3*x^14 + 46*x^13 + 115*x^12 + 176*x^11 + 212*x^10 + 226*x^9 + 228*x^8 + 214*x^7 + 170*x^6 + 122*x^5 + 79*x^4 + 42*x^3 + 19*x^2 + 6*x + 1) / ((1 - x^2)*(1 - x^3)*(1 - x^6)^2) + O(x^50)) \\ Colin Barker, Feb 14 2018

Formula

G.f.: (12*x^20 + 16*x^19 - 20*x^17 - 27*x^16 - 8*x^15 + 3*x^14 + 46*x^13 + 115*x^12 + 176*x^11 + 212*x^10 + 226*x^9 + 228*x^8 + 214*x^7 + 170*x^6 + 122*x^5 + 79*x^4 + 42*x^3 + 19*x^2 + 6*x + 1) / ((1 - x^2)*(1 - x^3)*(1 - x^6)^2).
a(n) = a(n-2) + a(n-3) - a(n-5) + 2*a(n-6) - 2*a(n-8) - 2*a(n-9) + 2*a(n-11) - a(n-12) + a(n-14) + a(n-15) - a(n-17) for n>17. - Colin Barker, Feb 14 2018

A008576 Coordination sequence for planar net 4.8.8.

Original entry on oeis.org

1, 3, 5, 8, 11, 13, 16, 19, 21, 24, 27, 29, 32, 35, 37, 40, 43, 45, 48, 51, 53, 56, 59, 61, 64, 67, 69, 72, 75, 77, 80, 83, 85, 88, 91, 93, 96, 99, 101, 104, 107, 109, 112, 115, 117, 120, 123, 125, 128, 131, 133
Offset: 0

Views

Author

Keywords

Comments

Also, growth series for the affine Coxeter (or Weyl) groups B_2. - N. J. A. Sloane, Jan 11 2016

References

  • N. Bourbaki, Groupes et Algèbres de Lie, Chap. 4, 5 and 6, Hermann, Paris, 1968. See Chap. VI, Section 4, Problem 10b, page 231, W_a(t).
  • A. V. Shutov, On the number of words of a given length in plane crystallographic groups (Russian), Zap. Nauchn. Sem. S.-Peterburg. Otdel. Mat. Inst. Steklov. (POMI) 302 (2003), Anal. Teor. Chisel i Teor. Funkts. 19, 188--197, 203; translation in J. Math. Sci. (N.Y.) 129 (2005), no. 3, 3922-3926 [MR2023041]. See Table 1.

Crossrefs

List of coordination sequences for uniform planar nets: A008458 (the planar net 3.3.3.3.3.3), A008486 (6^3), A008574 (4.4.4.4 and 3.4.6.4), A008576 (4.8.8), A008579(3.6.3.6), A008706 (3.3.3.4.4), A072154 (4.6.12), A219529(3.3.4.3.4), A250120 (3.3.3.3.6), A250122 (3.12.12).
For partial sums see A008577.
The growth series for the finite Coxeter (or Weyl) groups B_3 through B_12 are A161696-A161699, A161716, A161717, A161733, A161755, A161776, A161858. These are all rows of A128084. The growth series for the affine Coxeter (or Weyl) groups B_2 through B_12 are A008576, A008137, A267167-A267175.

Programs

  • Maple
    if n mod 3 = 0 then 8*n/3 elif n mod 3 = 1 then 8*(n-1)/3+3 else 8*(n-2)/3+5 fi;
  • Mathematica
    cspn[n_]:=Module[{c=Mod[n,3]},Which[c==0,(8n)/3,c==1,(8(n-1))/3+3,True,(8(n-2))/3+5]]; Join[{1},Array[cspn,50]] (* or *) Join[{1}, LinearRecurrence[ {1,0,1,-1},{3,5,8,11},50]] (* Harvey P. Dale, Nov 24 2011 *)
  • PARI
    a(n)=([0,1,0,0; 0,0,1,0; 0,0,0,1; -1,1,0,1]^n*[1;3;5;8])[1,1] \\ Charles R Greathouse IV, Apr 08 2016

Formula

G.f.: ((1+x)^2*(1+x^2))/((1-x)^2*(1+x+x^2)). - Ralf Stephan, Apr 24 2004
a(0)=1, a(1)=3, a(2)=5, a(3)=8, a(4)=11, a(n) = a(n-1) + a(n-3) - a(n-4). - Harvey P. Dale, Nov 24 2011
a(0)=1; thereafter a(3k)=8k, a(3k+1)=8k+3, a(3k+2)=8k+5. - N. J. A. Sloane, Dec 22 2015
The above g.f. and recurrence were originally empirical observations, but I now have a proof (details will be added later). This also justifies the Maple and Mma programs and the b-file. - N. J. A. Sloane, Dec 22 2015
Sum of alternate terms of A042965 (numbers not congruent to 2 mod 4), such that A042965(n) = A042965(n+1) + A042965(n-1). - Gary W. Adamson, Sep 12 2007
a(n) = (2/9)*(12*n + (3/2)*A102283(n)) for n > 0. - Stefano Spezia, Aug 07 2022
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