A172515 First differences of A172513.

3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3, 3, 3, 4, 3

Offset: 1

Author

Stephen Crowley, Feb 05 2010

Keywords

• nonn

Comments

This sequence appears to have only '3's and '4's. Indices of '4's seem to be given by A322408, but this is true only for n < 95: then the next term in A322408 is 95, but only a(96) = 4. - M. F. Hasler, Apr 19 2019

Crossrefs

Cf. A172513, A167389.

Programs

PARI

(D(v)=v[^1]-v[^-1]); A172515_vec(N)=D(A172513_upto(N*7\2)) \\ M. F. Hasler, Apr 11 2019

Extensions

Keyword "hard" removed by M. F. Hasler, Apr 11 2019