login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

a(n) = A002487(1+A323247(n)) = A324288(A156552(n)).
6

%I #9 Feb 20 2019 21:43:08

%S 1,1,1,3,1,4,1,2,5,5,1,3,1,6,7,8,1,2,1,4,9,7,1,13,7,8,5,5,1,3,1,7,11,

%T 9,10,12,1,10,13,18,1,4,1,6,8,11,1,12,9,2,15,7,1,11,13,23,17,12,1,19,

%U 1,13,11,13,16,5,1,8,19,3,1,13,1,14,7,9,13,6,1,17,10,15,1,26,19,16,21,28,1,18,17,10,23,17,22,23,1,2

%N a(n) = A002487(1+A323247(n)) = A324288(A156552(n)).

%C Like A323902, this also has quite a moderate growth rate, even though a certain subset of terms of A156552 soon grow quite big.

%H Antti Karttunen, <a href="/A324116/b324116.txt">Table of n, a(n) for n = 1..16384</a>

%H Antti Karttunen, <a href="/A324116/a324116.txt">Data supplement: n, a(n) computed for n = 1..65537</a>

%H <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>

%H <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>

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

%F a(n) = A002487(1+A323247(n)) = A324288(A156552(n)).

%F a(p) = 1 for all primes p.

%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); }; \\ So we use this one, modified from the one given in A002487

%o A005187(n) = { my(s=n); while(n>>=1, s+=n); s; };

%o A064989(n) = {my(f); f = factor(n); if((n>1 && f[1,1]==2), f[1,2] = 0); for (i=1, #f~, f[i,1] = precprime(f[i,1]-1)); factorback(f)};

%o A156552(n) = if(1==n, 0, if(!(n%2), 1+(2*A156552(n/2)), 2*A156552(A064989(n))));

%o A324288(n) = A002487(1+A005187(n));

%o A324116(n) = A324288(A156552(n));

%Y Cf. A002487, A005187, A156552, A323247, A323902, A324115, A324288.

%K nonn

%O 1,4

%A _Antti Karttunen_, Feb 20 2019