A108664 In the decimal expansion of Pi, lengths of sublists ending with 9.

6, 7, 2, 16, 8, 4, 2, 1, 10, 3, 4, 17, 1, 20, 22, 7, 15, 25, 11, 7, 3, 3, 6, 9, 6, 33, 2, 10, 25, 10, 34, 3, 5, 5, 12, 3, 32, 3, 8, 15, 2, 2, 4, 11, 7, 19, 1, 5, 17, 5, 9, 2, 3, 26, 2, 4, 9, 7, 4, 11, 8, 22, 42, 3, 19, 6, 11, 11, 4, 3, 4, 8, 1, 8, 4, 14, 6, 9, 1, 14, 1, 1, 1, 1, 1, 5, 5, 1, 5, 11

Offset: 1

Author

Zak Seidov, Jun 17 2005

Keywords

• base
• nonn

Comments

Take the decimal expansion of Pi: s={3,1,4,1,5,9,2,6,5,3,5,8,9,7,9,3, 2,3,8,4,6,2,6,4,3,3,8,3,2,7,9,5,0,2,8,8,4}. Split s into sublists each ending with 9: {{3,1,4,1,5,9}, {2,6,5,3,5,8,9}, {7,9}, {3,2,3,8,4,6,2,6,4,3,3,8,3,2,7,9}, {5,0,2,8,8,4,1,9}}. The sequence gives the lengths of the sublists: 6,7,2,16,8,4,2,1,10,3,4,17,1,20,22,7. Cf. A053753 (positions of 9's in the decimal expansion of Pi).

Crossrefs

Cf. A000796, A037007, A053753, A108663, A139727, A014974.

Formula

a(n) = A053753(n+1) - A053753(n).