A255821 Numbers of words on {0,1,...,36} having no isolated zeros.
1, 36, 1297, 46729, 1683577, 60656797, 2185374961, 78735837637, 2836736138665, 102203420474269, 3682238546710945, 132665625592223221, 4779746882367738841, 172207232713967895181, 6204372685172893559377, 223534399861459456068709
Offset: 0
Links
- Colin Barker, Table of n, a(n) for n = 0..642
- Index entries for linear recurrences with constant coefficients, signature (37,-36,36).
Programs
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Mathematica
RecurrenceTable[{a[0] == 1, a[1] == 36, a[2]== 1297, a[n] == 37 a[n - 1] - 36 a[n - 2] + 36 a[n - 3]}, a[n], {n, 0, 15}] LinearRecurrence[{37,-36,36}, {1, 36, 1297}, 100] (* G. C. Greubel, Jun 02 2016 *)
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PARI
Vec(-(x^2-x+1)/(36*x^3-36*x^2+37*x-1) + O(x^100)) \\ Colin Barker, Mar 09 2015
Formula
G.f.: -(x^2 - x + 1)/(36*x^3 - 36*x^2 + 37*x - 1). - Colin Barker, Mar 09 2015
a(n) = 37*a(n-1) - 36*a(n-2) + 36*a(n-3). - G. C. Greubel, Jun 02 2016
Comments