A077146 a(n) = floor((concatenation of next (n+1) numbers) / (concatenation of next n numbers)).

23, 19, 173, 14093, 145, 137, 131, 127, 124, 121, 119, 117, 116453592, 11416794012, 1141, 1132, 1124, 1116, 1110, 1104, 1099, 1094, 1090, 1086, 1083, 1079, 1076, 1073, 1071, 1068, 1066, 1064, 1062, 1060, 1058, 1057, 1055, 1053, 1052, 1051, 1049, 1048, 1047

Offset: 1

Author

Amarnath Murthy, Oct 30 2002

Keywords

• base
• nonn

Comments

The numerator numbers to be concatenated are taken from 2,3,4,... and the denominator numbers from 1,2,3,... - Lars Blomberg, Mar 18 2012

Examples

			a(1) = floor(23/1) = 23.
a(2) = floor(456/23) = 19.
a(3) = floor(78910/456) = 173.
		

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..1413

Crossrefs

Cf. A053067.

Programs

Python

def b(n): return int("".join(map(str, range((n-1)*n//2+1, n*(n+1)//2+1))))
def a(n): return b(n+1)//b(n)
print([a(n) for n in range(1, 44)]) # Michael S. Branicky, Jul 31 2022

Formula

a(n) = floor(A053067(n+1)/A053067(n)). - Michel Marcus, Jul 31 2022

Extensions

a(7)-a(36) from Lars Blomberg, Mar 18 2012

a(37) and beyond from Michael S. Branicky, Jul 31 2022