A351253 - OEIS

%I #8 Feb 06 2022 21:25:08

%S 0,1,2,1,4,5,6,7,8,7,4,11,12,13,14,7,16,17,18,19,14,19,22,23,24,13,26,

%T 25,28,29,30,31,32,31,34,5,36,37,38,37,34,41,12,43,44,37,46,47,48,19,

%U 38,49,52,53,54,49,26,55,58,59,60,61,62,31,64,65,66,67,68,67,34,71,72,73,74,61,76,47,78,79,74,79

%N a(n) = A276085(A351251(n)).

%H Antti Karttunen, <a href="/A351253/b351253.txt">Table of n, a(n) for n = 0..30030</a>

%F a(n) = A276085(A351251(n)) = A276085(A276086(n) / A324198(n)).

%F a(n) = n - A351254(n).

%o (PARI)

%o A002110(n) = prod(i=1,n,prime(i));

%o A276085(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*A002110(primepi(f[k, 1])-1)); };

%o A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };

%o A351251(n) = { my(u=A276086(n)); (u/gcd(n, u)); };

%o A351253(n) = A276085(A351251(n));

%Y Cf. A276085, A276086, A324198, A351251, A351254.

%Y Cf. also A351233.

%K nonn,easy

%O 0,3

%A _Antti Karttunen_, Feb 05 2022