A324293 - OEIS

%I #6 Feb 23 2019 07:22:57

%S 1,2,1,3,2,2,1,4,5,4,2,3,3,2,2,5,4,10,3,8,1,4,2,4,5,8,3,3,4,4,1,6,2,8,

%T 2,19,7,4,3,12,8,2,5,8,10,4,2,5,10,16,4,9,8,4,4,4,3,12,4,8,5,2,5,7,8,

%U 4,5,6,2,4,4,20,11,10,5,9,2,8,3,16,13,6,8,3,8,6,4,12,12,18,3,8,1,4,4,6,9,34,10,27,12,8,5,18,2

%N a(n) = A002487(sigma(n)).

%H Antti Karttunen, <a href="/A324293/b324293.txt">Table of n, a(n) for n = 1..16384</a>

%H Antti Karttunen, <a href="/A324293/a324293.txt">Data supplement: n, a(n) computed for n = 1..65537</a>

%H <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>

%H <a href="/index/St#Stern">Index entries for sequences related to Stern's sequences</a>

%F a(n) = A002487(A000203(n)).

%o (PARI)

%o A002487(n) = { my(s=sign(n), a=1, b=0); n = abs(n); while(n>0, if(bitand(n, 1), b+=a, a+=b); n>>=1); (s*b); }; \\ Modified from the one given in A002487, sign not actually needed here.

%o A324293(n) = A002487(sigma(n));

%Y Cf. A000203, A002487, A324287, A324294.

%K nonn

%O 1,2

%A _Antti Karttunen_, Feb 22 2019