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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A299263 Partial sums of A299257.

Original entry on oeis.org

1, 6, 18, 40, 76, 132, 214, 325, 469, 652, 878, 1150, 1474, 1856, 2298, 2803, 3379, 4032, 4762, 5572, 6472, 7468, 8558, 9745, 11041, 12452, 13974, 15610, 17374, 19272, 21298, 23455, 25759, 28216, 30818, 33568, 36484, 39572, 42822, 46237, 49837, 53628, 57598
Offset: 0

Views

Author

N. J. A. Sloane, Feb 07 2018

Keywords

Crossrefs

Cf. A299257.
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 + x)*(1 + x + x^2 + 3*x^3 - x^4 + 5*x^5 - 3*x^6 + 4*x^7 - 2*x^8) / ((1 - x)^4*(1 + x^2)^2) + O(x^60)) \\ Colin Barker, Feb 09 2018

Formula

From Colin Barker, Feb 09 2018: (Start)
G.f.: (1 + x)*(1 + x + x^2 + 3*x^3 - x^4 + 5*x^5 - 3*x^6 + 4*x^7 - 2*x^8) / ((1 - x)^4*(1 + x^2)^2).
a(n) = 4*a(n-1) - 8*a(n-2) + 12*a(n-3) - 14*a(n-4) + 12*a(n-5) - 8*a(n-6) + 4*a(n-7) - a(n-8) for n>8.
(End)
5*a(n) = 2*(2*n+1)*(2*n^2+2*n+9)/3 - A138019(n). - R. J. Mathar, Feb 12 2021

A135557 Consider the primes which are congruent to 2 or 3 modulo 5. List the sum of any consecutive pair if that sum is congruent to 0 modulo 10.

Original entry on oeis.org

10, 20, 30, 40, 60, 80, 90, 100, 120, 140, 180, 200, 210, 220, 240, 320, 330, 340, 390, 420, 450, 460, 490, 520, 540, 560, 600, 620, 630, 700, 720, 740, 780, 830, 900, 920, 930, 990, 1070, 1120, 1140, 1180, 1200, 1220, 1230, 1260, 1290, 1300, 1350, 1360
Offset: 1

Views

Author

Daniele Corradetti (d.corradetti(AT)gmail.com), Feb 28 2008

Keywords

Examples

			3+7 == 10; 13+17 == 30; 17+23 == 40; 23+37 == 60; 37+43 == 80;...
		

Crossrefs

Programs

  • Mathematica
    Select[ Plus @@@ Partition[ Select[ Prime@ # & /@ Range@125, Mod[ #, 5] == 2 || Mod[ #, 5] == 3 &], 2, 1], Mod[ #, 10] == 0 &] (* Robert G. Wilson v, Feb 29 2008 *)

Extensions

Edited, corrected and extended by Robert G. Wilson v, Feb 29 2008
Showing 1-2 of 2 results.