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A301152
Coordination sequence T3 for Zeolite Code OWE.
1
1, 4, 11, 22, 32, 49, 77, 109, 139, 163, 197, 250, 310, 357, 398, 456, 526, 603, 676, 744, 819, 903, 999, 1097, 1191, 1283, 1386, 1504, 1619, 1732, 1850, 1978, 2113, 2244, 2374, 2517, 2673, 2825, 2973, 3125, 3287, 3460, 3638, 3813, 3982, 4158, 4348
OFFSET
0,2
FORMULA
From Chai Wah Wu, Feb 03 2021: (Start)
a(n) = a(n-1) - 2*a(n-2) + 2*a(n-3) - 2*a(n-4) + 3*a(n-5) - 2*a(n-6) + 4*a(n-7) - 3*a(n-8) + 4*a(n-9) - 4*a(n-10) + 3*a(n-11) - 4*a(n-12) + 2*a(n-13) - 3*a(n-14) + 2*a(n-15) - 2*a(n-16) + 2*a(n-17) - a(n-18) + a(n-19) for n > 19.
G.f.: -(x + 1)*(x^18 + 2*x^17 + 7*x^16 + 10*x^15 + 16*x^14 + 28*x^13 + 32*x^12 + 49*x^11 + 44*x^10 + 54*x^9 + 44*x^8 + 49*x^7 + 32*x^6 + 28*x^5 + 16*x^4 + 10*x^3 + 7*x^2 + 2*x + 1)/((x - 1)^3*(x^2 + 1)*(x^2 - x + 1)*(x^2 + x + 1)*(x^4 + x^3 + x^2 + x + 1)*(x^6 + x^5 + x^4 + x^3 + x^2 + x + 1)). (End)
CROSSREFS
Sequence in context: A301115 A050843 A360039 * A301083 A024990 A055635
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Mar 18 2018
STATUS
approved