A033617 -id:A033617

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A299903

Partial sums of A033617.

+20
1

1, 5, 14, 31, 59, 100, 156, 229, 322, 439, 585, 765, 981, 1234, 1525, 1854, 2223, 2637, 3103, 3627, 4213, 4863, 5575, 6348, 7184, 8086, 9059, 10110, 11246, 12470, 13783, 15186, 16678, 18259, 19932, 21701, 23571, 25549, 27642, 29853, 32182, 34629, 37192, 39870, 42667, 45590, 48647, 51845, 55189, 58679, 62312

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

COMMENTS

First 127 terms computed by Davide M. Proserpio using ToposPro.

LINKS

Table of n, a(n) for n=0..50.

CROSSREFS

Cf. A033617.

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Feb 21 2018

STATUS

approved

A033616

Coordination sequence T1 for Zeolite Code TSC.

+10
3

1, 4, 9, 16, 25, 37, 53, 74, 99, 125, 151, 177, 205, 238, 279, 328, 381, 434, 483, 528, 574, 627, 690, 762, 840, 919, 995, 1068, 1140, 1214, 1294, 1382, 1477, 1577, 1681, 1787, 1892, 1995, 2096, 2197, 2303, 2419, 2546, 2681, 2819, 2954, 3082, 3205, 3329

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

COMMENTS

First 127 terms computed by Davide M. Proserpio using ToposPro.

LINKS

R. W. Grosse-Kunstleve, Table of n, a(n) for n = 0..1000(terms 0..127 from Davide M. Proserpio)

V. A. Blatov, A. P. Shevchenko, D. M. Proserpio, Applied Topological Analysis of Crystal Structures with the Program Package ToposPro, Cryst. Growth Des. 2014, 14, 3576-3586.

R. W. Grosse-Kunstleve, Coordination Sequences and Encyclopedia of Integer Sequences

Sean A. Irvine, Generating Functions for Coordination Sequences of Zeolites, after Grosse-Kunstleve, Brunner, and Sloane

International Zeolite Association, Database of Zeolite Structures

Reticular Chemistry Structure Resource (RCSR), The tsc tiling (or net)

FORMULA

G.f.: (1 + x)^3 * (1 + x^2) * (1 - x + 2*x^2 - x^3 + 3*x^4 - x^5 + 4*x^6 - x^7 + 4*x^8 - x^9 + 4*x^10 - x^11 + 4*x^12 - x^13 + 3*x^14 - x^15 + 2*x^16 - x^17 + x^18) / ((1 - x)^3 * (1 - x + x^2 - x^3 + x^4) * (1 + x + x^2 + x^3 + x^4) * (1 + x^3 + x^6) * (1 + x + x^2 + x^3 + x^4 + x^5 + x^6)). - Colin Barker, Dec 19 2015

From N. J. A. Sloane, Feb 22 2018 (Start)

The following is a another conjectured recurrence, found by gfun, using the command rec:=gfun[listtorec](t1, a(n)); (where t1 is a list of the initial terms) suggested by Paul Zimmermann.

Note: this should not be used to extend the sequence.

0 = (-38*n^3-836*n^2-5351*n)*a(n)+(-76*n^2-798*n)*a(n+1)+(-38*n^3-912*n^2-6149*n)*a(n+2)+(-38*n^3-988*n^2-6947*n)*a(n+3)+(-38*n^3-1064*n^2-7745*n)*a(n+4)+(-38*n^3-1140*n^2 -8543*n)*a(n+5)+(-76*n^3-2052*n^2-14692*n)*a(n+6)

+ (-532*n^2-5586*n)*a(n+7)+(-76*n^3-2204*n^2-16288*n)*a(n+8)+(-684*n^2-7182*n)*a(n+9)+(-684*n^2 -7182*n)*a(n+10)+(-684*n^2-7182*n)*a(n+11)+(-684*n^2-7182*n)*a(n+12)+(76*n^3+ 988*n^2+3520*n)*a(n+13)+(-532*n^2-5586*n)*a(n+14)+(76*n^3+1140*n^2+5116*n)*a(n+15)

+ (38*n^3+456*n^2+1361*n)*a(n+16)+(38*n^3+532*n^2+2159*n)*a(n+17)+(38*n^3+608*n^2+2957*n)*a(n+18)+(38*n^3+684*n^2+3755*n)*a(n+19)+(-76*n^2-798*n)*a(n+20)+(38*n^3+760*n^2+4553*n)*a(n+21), with

a(0) = 1, a(1) = 4, a(2) = 9, a(3) = 16, a(4) = 25, a(5) = 37, a(6) = 53, a(7) = 74, a(8) = 99, a(9) = 125, a(10) = 151, a(11) = 177, a(12) = 205, a(13) = 238, a(14) = 279, a(15) = 328, a(16) = 381, a(17) = 434, a(18) = 483, a(19) = 528, a(20) = 574, a(21) = 627

(End)