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%I #9 Mar 31 2012 13:48:30
%S 1,32,654,98710,1514131211,212019181716,28272625242322,
%T 3635343332313029,454443424140393837,55545352515049484746,
%U 6665646362616059585756,787776757473727170696867,91908988878685848382818079,9998979695949392105104103102101100
%N 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).
%C 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).
%e 1, then a concatenation of a permutation of 2 and 3, then a concatenation of a permutation of 4, 5 and 6.
%o (PARI 2.4.2) a(n)=eval(concat(vecsort(vector(n, i, Str(i+n*(n-1)/2)),,4)))
%Y Cf. A076068, A080479, A080480, A192392.
%K nonn,easy,less,base
%O 1,2
%A _M. F. Hasler_, Jun 29 2011
%E Definition modified to obtain a new sequence different from (earlier duplicate) A080480. M. F. Hasler, Jun 29 2011.
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