A186192 First digit of pentanacci numbers A000322.

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

Author

Carmine Suriano, Feb 14 2011

Keywords

• nonn
• base

Comments

Sequence obeys Benford law about distribution of first digits in a sequence P(n)=Log(1+1/n).

Examples

			a(15)=1 since Penta(15)=1921.
		

Links

• Indranil Ghosh, Table of n, a(n) for n = 1..10000
• Index entries for sequences related to Benford's law

Crossrefs

Cf. A000322.

Programs

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 *)