A109070 Number of digits in numbers appearing in A108225.

1, 1, 1, 1, 2, 2, 4, 7, 13, 25, 50, 99, 196, 392, 783, 1566, 3131, 6261, 12521, 25042, 50084, 100166, 200332, 400663, 801325, 1602649, 3205298, 6410595, 12821190, 25642379, 51284758

Offset

0,5

Comments

Starting with a(14)=783, a(n) = 2*a(n-1) - (1 or 0).

Links

Table of n, a(n) for n=0..30.

Example

A109070(10)=50 because A108225(10)=16217557574922386301420536972254869595782763547562 has 50 digits.

Mathematica

nxt[{a_, b_}]:={b, ((a+b)(b-a+1))/2}; Join[{1}, IntegerLength/@ Transpose[ NestList[nxt, {0, 2}, 31]][[2]]] (* Harvey P. Dale, Feb 14 2012 *)

Crossrefs

Cf. A108225.

Sequence in context: A325908 A153970 A067953 * A169973 A300353 A049868

Adjacent sequences: A109067 A109068 A109069 * A109071 A109072 A109073

Keyword

base,nonn

Author

Zak Seidov, Jun 18 2005

Status

approved