%I A075621
%S A075621 1,24,357,68912,1011131415,161718192024,21222325262733,2829303132343536,
%T A075621 373839404142434445,46474849505152535460,5556575859616263646571,
%U A075621 666768697072737475767780,787981828384858687888990110,919293949596979899100101102103112
%N A075621 Group the natural numbers so that the n-th group contains n numbers whose 
               concatenation is divisible by n: (1), (2, 4), (3, 5, 7), (6, 8, 9, 
               12), (10, 11, 13, 14, 15), (16, 17, 18, 19, 20, 24), ... Sequence 
               gives numbers formed by the concatenation.
%Y A075621 Cf. A075622, A075623, A075624, A075625.
%Y A075621 Sequence in context: A056634 A022748 A004325 this_sequence A137499 A122813 
               A028245
%Y A075621 Adjacent sequences: A075618 A075619 A075620 this_sequence A075622 A075623 
               A075624
%K A075621 base,nonn
%O A075621 1,2
%A A075621 Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Sep 30 2002
%E A075621 More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 
               29 2003