A378139 - OEIS

%I #42 Jan 29 2025 13:13:54

%S 2,3,23,11,19,263,167,103,487,1039,7951,5903,28319,107071,67231,

%T 590399,180799,344639,1480319,12181759,4757119,10871039,1611391,

%U 140167679,203082239,228248063,530237951,1812718591,5302379519,13295347711,12758476799,132953477119,1410065407

%N Smallest prime number such that the number of distinct prime factors with multiplicity of its 9's complement is equal to n. If no such number exists, return -1.

%H Michael S. Branicky, <a href="/A378139/b378139.txt">Table of n, a(n) for n = 1..1000</a> (terms 1..37 from Jean-Marc Rebert)

%e 2 is prime, 9-2 = 7 and bigomega(7) = 1.

%o (PARI) nc(n) = my(e=length(Str(n))); 10^e-1 - n; \\ A061601

%o a(n) = my(p=2); while (bigomega(nc(p)) != n, p = nextprime(p+1)); p; \\ _Michel Marcus_, Jan 08 2025

%Y Cf. A000040, A001221, A001222, A061601. A377471,

%K nonn,base

%O 1,1

%A _Jean-Marc Rebert_, Jan 08 2025