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Largest prime factor of A359124(n).
2

%I #9 Dec 20 2022 18:49:28

%S 2,13,31,19,6173,123457,154321,333667,333667,3388877,4281283,2630197,

%T 26798700427,8663199947,2523244037,12873492085621702963,

%U 32929947197382727,17539959825403,71595329159622797,325339942922532262019,9999103057380477280607,17465868005034957301,1423364280511

%N Largest prime factor of A359124(n).

%C Has the same relation to A359124 as A075032 does to A007908. Suggested by A069048.

%t FactorInteger[#][[-1,1]]&/@Table[FromDigits[Flatten[IntegerDigits/@Range[n]]]+1,{n,30}] (* _Harvey P. Dale_, Dec 20 2022 *)

%o (Python)

%o from sympy import factorint

%o def a(n): return max(factorint(int("".join(map(str, range(1, n+1)))) + 1))

%o print([a(n) for n in range(1, 24)]) # _Michael S. Branicky_, Dec 20 2022

%Y Cf. A007908, A069048, A075032, A359124.

%K nonn,base

%O 1,1

%A _N. J. A. Sloane_, Dec 20 2022