A164530 - OEIS

%I #18 Mar 21 2024 08:37:46

%S 1,2,4,6,8,12,14,16,18,20,22,24,26,28,32,35,36,42,44,48,52,56,58,64,

%T 66,68,72,78,80,88,90,96,100,104,108,117,118,120,124,128,130,136,138,

%U 144,150,152,154,160,162,168,172,174,176,184,188,192,196,200,202,204,206

%N a(1)=1. a(n) = the smallest multiple of d(n) that is > a(n-1), where d(n) = the number of positive divisors of n.

%H John Tyler Rascoe, <a href="/A164530/b164530.txt">Table of n, a(n) for n = 1..10000</a>

%t Block[{n = 1, d}, NestList[(d = DivisorSigma[0, ++n]) * Floor[# / d + 1] &, 1, 100]] (* _Paolo Xausa_, Mar 21 2024 *)

%o (PARI)

%o A164530_list(nmax)={my(A=vector(nmax)); A[1]=1;

%o for(k=2, nmax, my(i=1); while(numdiv(k)*i<A[k-1]+1, i+=1); A[k]=numdiv(k)*i); A}

%o A164530_list(100) \\ _John Tyler Rascoe_, Mar 20 2024

%Y Cf. A000005, A164531.

%K nonn,easy

%O 1,2

%A _Leroy Quet_, Aug 15 2009

%E Extended by _Ray Chandler_, Mar 15 2010