A192392 Largest multiple of n which can be formed as concatenation of the next n numbers, {1+n(n-1)/2,...,n(n+1)/2} (written in decimal), or 0 if no such number exists.

1, 32, 654, 97108, 1413121115, 212019181716, 28272625222324, 3635343331293032, 454443424140393837, 55545352514948474650, 6665646362616059585756, 787776757473727170696768, 91908988878685848382817980, 9998979695949392105104103101100102

Offset: 1

Author

M. F. Hasler, Jun 29 2011

Keywords

• nonn
• base

Comments

Equal to A076069(n) whenever A076069(n) is a multiple of n. Less than or equal to A076072(n), where permutations of individual digits are allowed.

Crossrefs

Cf. A076068, A076069, A076072, A080479, A080480.

Programs

PARI

precperm(p)={ my(t); forstep( i=#p-1,1,-1, p[i]>p[i+1] && for( j=1,#t=vecsort( vecextract( p, 2^#p-2^(i-1) ),,4), t[j]A192392(n)={ my( d=vecsort( vector( n,i,Str( i+n*(n-1)/2 )),,4 ), t );
 for( i=1,n!, eval(concat(d))%n || break; d=precperm(d)); eval(concat(d))}