cp's OEIS Frontend

A328461 a(n) = A276156(n) / A002110(A007814(n)).

%I A328461 #17 Oct 18 2019 21:28:48
%S A328461 1,1,3,1,7,4,9,1,31,16,33,6,37,19,39,1,211,106,213,36,217,109,219,8,
%T A328461 241,121,243,41,247,124,249,1,2311,1156,2313,386,2317,1159,2319,78,
%U A328461 2341,1171,2343,391,2347,1174,2349,12,2521,1261,2523,421,2527,1264,2529,85,2551,1276,2553,426,2557,1279,2559,1,30031,15016,30033,5006
%N A328461 a(n) = A276156(n) / A002110(A007814(n)).
%C A328461 A276156(n) converts the binary expansion of n to a number whose primorial base representation has the same digits of 0's and 1's, thus each one of its terms is a unique sum of distinct primorial numbers. In this sequence that sum is then divided by the largest primorial that divides it, which only depends on the position of the least significant 1-bit in the binary expansion of the original n, that is, the 2-adic valuation of n.
%H A328461 Antti Karttunen, <a href="/A328461/b328461.txt">Table of n, a(n) for n = 1..8192</a>
%H A328461 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%H A328461 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%H A328461 <a href="/index/Pri#primorial_numbers">Index entries for sequences related to primorial numbers</a>
%F A328461 a(n) = A276156(n) / A002110(A007814(n)).
%F A328461 a(n) = A111701(A276156(n)).
%o A328461 (PARI)
%o A328461 A002110(n) = prod(i=1,n,prime(i));
%o A328461 A276156(n) = { my(p=2,pr=1,s=0); while(n,if(n%2,s += pr); n >>= 1; pr *= p; p = nextprime(1+p)); (s); };
%o A328461 A328461(n) = (A276156(n)/A002110(valuation(n,2)));
%Y A328461 Cf. A000265, A002110, A007814, A111701, A276154, A276156.
%Y A328461 Cf. A328462 (bisection, also row 1 of array A328464 which shows the same information in tabular form).
%Y A328461 Cf. A328471, A328472, A328473, A328474.
%K A328461 nonn
%O A328461 1,3
%A A328461 _Antti Karttunen_, Oct 16 2019