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A186192
First digit of pentanacci numbers A000322.
2
1, 1, 1, 1, 1, 5, 9, 1, 3, 6, 1, 2, 4, 9, 1, 3, 7, 1, 2, 5, 1, 2, 4, 8, 1, 3, 6, 1, 2, 4, 9, 1, 3, 7, 1, 2, 5, 1, 2, 4, 8, 1, 3, 6, 1, 2, 4, 9, 1, 3, 7, 1, 2, 5, 1, 2, 4, 8, 1, 3, 6, 1, 2, 4, 9, 1, 3, 6, 1, 2, 5, 1, 2, 4, 7, 1, 3, 6, 1, 2, 4, 8, 1, 3, 6, 1, 2, 5, 1, 2, 3, 7, 1, 2, 5, 1, 2, 4, 8, 1, 3, 6, 1, 2, 5
OFFSET
1,6
COMMENTS
Sequence obeys Benford law about distribution of first digits in a sequence P(n)=Log(1+1/n).
EXAMPLE
a(15)=1 since Penta(15)=1921.
MATHEMATICA
t = {1, 1, 1, 1, 1}; Do[AppendTo[t, t[[-1]] + t[[-2]] + t[[-3]] + t[[-4]] + t[[-5]]], {100}]; Table[IntegerDigits[i][[1]], {i, t}]
First[IntegerDigits[#]]&/@LinearRecurrence[{1, 1, 1, 1, 1}, {1, 1, 1, 1, 1}, 110] (* Harvey P. Dale, Mar 28 2013 *)
CROSSREFS
Cf. A000322.
Sequence in context: A377559 A274418 A127414 * A231532 A086201 A362742
KEYWORD
nonn,base
AUTHOR
Carmine Suriano, Feb 14 2011
STATUS
approved