login
A248675
Decimal expansion of r = sum_{n >= 0} floor(n/2)!/n!.
5
2, 7, 7, 6, 8, 8, 9, 6, 0, 9, 4, 0, 7, 9, 7, 9, 7, 2, 6, 9, 8, 1, 2, 4, 5, 1, 6, 3, 6, 1, 7, 1, 8, 8, 0, 6, 1, 8, 5, 3, 8, 4, 9, 8, 3, 6, 6, 5, 0, 9, 6, 1, 3, 1, 1, 3, 2, 7, 0, 5, 7, 5, 0, 9, 5, 9, 6, 1, 1, 0, 3, 8, 8, 4, 9, 9, 5, 2, 2, 6, 7, 1, 0, 8, 1, 7
OFFSET
1,1
LINKS
FORMULA
r = sum_{n >= 0} p(2,n)*n!/(2*n + 1)!, where p(k,n) is defined at A248664.
EXAMPLE
r = 2.7768896094079797269812451636...
MAPLE
evalf(sum(floor(n/2)!/n!, n=0..infinity), 120); # Vaclav Kotesovec, Oct 17 2014
MATHEMATICA
x = N[Sum[Floor[n/2]!/n!, {n, 0, 200}], 120]
RealDigits[x][[1]] (* A248675 *)
x = N[Sum[Floor[n/3]!/n!, {n, 0, 200}], 120]
RealDigits[x][[1]] (* A248676 *)
x = N[Sum[Floor[n/4]!/n!, {n, 0, 200}], 120]
RealDigits[x][[1]] (* A248677 *)
CROSSREFS
KEYWORD
nonn,easy,cons
AUTHOR
Clark Kimberling, Oct 11 2014
STATUS
approved