A076069 Largest number formed as concatenation of a permutation of the n consecutive numbers 1+n(n-1)/2, ..., n(n+1)/2 (written in decimal).

1, 32, 654, 98710, 1514131211, 212019181716, 28272625242322, 3635343332313029, 454443424140393837, 55545352515049484746, 6665646362616059585756, 787776757473727170696867, 91908988878685848382818079, 9998979695949392105104103102101100

Offset: 1

Author

M. F. Hasler, Jun 29 2011

Keywords

• nonn
• easy
• less
• base

Comments

Nontrivial (i.e., different from concatenation in reverse order) whenever a number of the form 10^k is in the considered range of n numbers; then a(n) is given as concatenation (10^k-1)...(1+n(n-1)/2)(n(n+1)/2)...(10^k).

Examples

			1, then a concatenation of a permutation of 2 and 3, then a concatenation of a permutation of 4, 5 and 6.
		

Crossrefs

Cf. A076068, A080479, A080480, A192392.

Extensions

Definition modified to obtain a new sequence different from (earlier duplicate) A080480. M. F. Hasler, Jun 29 2011.