cp's OEIS Frontend

A347120 Square root of the largest square dividing A005940(1+(3*A156552(n))): a(n) = A000188(A332449(n)).

%I A347120 #8 Apr 09 2022 08:46:55
%S A347120 1,2,3,1,5,4,7,1,1,6,11,1,13,10,9,3,17,2,19,5,15,14,23,1,1,22,1,7,29,
%T A347120 8,31,3,21,26,25,1,37,34,33,5,41,12,43,11,1,38,47,3,1,2,39,13,53,2,35,
%U A347120 7,51,46,59,1,61,58,7,9,55,20,67,17,57,18,71,1,73,62,3,19,49,28,79,15,5,74,83,11,65,82,69,11,89
%N A347120 Square root of the largest square dividing A005940(1+(3*A156552(n))): a(n) = A000188(A332449(n)).
%H A347120 Antti Karttunen, <a href="/A347120/b347120.txt">Table of n, a(n) for n = 1..12000</a>
%H A347120 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>
%F A347120 a(n) = A000188(A332449(n)).
%F A347120 a(n) = A000196(A332449(n)/A347119(n)).
%F A347120 a(p) = p for all primes p.
%o A347120 (PARI)
%o A347120 A000188(n) = core(n, 1)[2]; \\ This function from A000188
%o A347120 A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };
%o A347120 A156552(n) = { my(f = factor(n), p, p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res };
%o A347120 A332449(n) = A005940(1+(3*A156552(n)));
%o A347120 A347120(n) = A000188(A332449(n));
%Y A347120 Cf. A000188, A000196, A005940, A007913, A156552, A332449, A347119.
%K A347120 nonn
%O A347120 1,2
%A A347120 _Antti Karttunen_, Aug 22 2021