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A114027 Composite numbers such that the n-th partial concatenation is a multiple of composite(n). 1

%I

%S 4,8,8,16,10,8,6,15,20,4,20,16,12,24,25,12,8,28,20,16,44,38,35,44,16,

%T 32,40,8,32,25,26,4,35,50,35,24,6,25,52,58,56,40,38,82,24,55,68,4,68,

%U 60,72,66,75,28,78,38,40,125,16,44,90,34,20,24,60,78,36,12

%N Composite numbers such that the n-th partial concatenation is a multiple of composite(n).

%e A002808(2)=6 divides 48, A002808(3)=8 divides 488, A002808(4)=9 divides 48816 etc. - _R. J. Mathar_, Aug 31 2007

%o (PARI) lista(nn) = {my(m, s=""); forcomposite(k=4, nn, m=4; while(eval(Str(s, m))%k || isprime(m), m++); print1(m, ", "); s=Str(s, m)); } \\ _Jinyuan Wang_, May 30 2020

%Y Cf. A002808, A114028.

%K nonn,base

%O 1,1

%A _Amarnath Murthy_, Nov 13 2005

%E Corrected and extended by _R. J. Mathar_, Aug 31 2007

%E More terms from _Jinyuan Wang_, May 30 2020

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Last modified January 31 03:33 EST 2023. Contains 359947 sequences. (Running on oeis4.)