A108663 In the decimal expansion of Pi, lengths of sublists with alternative parity.

2, 1, 3, 2, 3, 1, 4, 1, 1, 6, 2, 1, 1, 1, 3, 5, 4, 1, 8, 1, 1, 3, 2, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 10, 2, 5, 1, 3, 2, 2, 3, 2, 2, 2, 1, 5, 3, 3, 1, 4, 1, 1, 2, 5, 3, 1, 1, 3, 3, 1, 4, 3, 1, 4, 4, 1, 1, 4, 1, 2, 1, 1, 3, 1, 1, 1, 2, 1, 4, 6, 1, 2, 2, 1, 2, 1, 1, 1, 2, 6, 1, 1, 3, 2, 4, 3, 1, 3, 2, 4, 3, 2, 1, 1, 2

Offset: 1

Author

Zak Seidov, Jun 17 2005

Keywords

• base
• nonn

Comments

Take the decimal expansion of Pi: s={3,1,4,1,5,9,2,6,5,3,5,8,9,7,9,3,2,3,8,4,6,2,6,4,3,3,8,3,2,7,9,5,0,2,8,8,4,1,9}. Split s into sublists each with digits of the same parity:{{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}}. The sequence gives the lengths of the sublists: 2,1,3,2,3,1,4,1,1,6,2,1,1,1,3,5,4,1,8.

Programs

Mathematica

A108663=Length/@Split[RealDigits[N[Pi, 300]][[1]], Mod[ #1-#2, 2]==0&]