A248683 Decimal expansion of r = sum{(floor(n/3)!)^3/n!, n >= 0}.
2, 7, 3, 0, 2, 5, 6, 3, 7, 6, 9, 6, 3, 3, 6, 1, 3, 8, 5, 8, 0, 4, 9, 8, 3, 2, 7, 4, 4, 7, 7, 1, 9, 7, 6, 2, 7, 1, 9, 7, 1, 2, 4, 1, 6, 3, 0, 1, 5, 9, 6, 2, 6, 9, 3, 2, 7, 0, 5, 2, 5, 1, 6, 3, 7, 6, 0, 2, 6, 1, 9, 7, 5, 9, 1, 8, 6, 8, 3, 7, 1, 4, 6, 1, 7, 4
Offset: 1
Examples
r = 2.7302563769633613858049832744771976271...
Links
- Clark Kimberling, Table of n, a(n) for n = 1..1000
Programs
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Mathematica
RealDigits[Sum[(Floor[n/3])!^3/n!, {n, 0, 400}], 10, 111][[1]] -
PARI
suminf(n=0, ((n\3)!)^3/n!) \\ Michel Marcus, Feb 23 2016
Formula
r = sum{(n!^3)*p(3,n)/(3*n + 2)!, n >= 0}, where p(k,n) is defined at A248664.