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A379229
Difference A003961(k)-(2*k) computed for the natural numbers k for which k and A003961(k) are relatively prime, where A003961 is fully multiplicative with a(prime(i)) = prime(i+1).
2
-1, -1, -1, 1, -3, -3, 11, 7, 1, -9, -9, 5, 49, -15, -15, 23, 13, -5, -17, -1, -1, 71, 43, -27, -25, 179, -1, -11, -33, -7, 7, 109, -39, -39, 29, -5, -41, 23, 47, -7, 49, -47, -19, 185, 1, -23, -57, -55, -13, 149, 601, -11, -63, 35, 7, -69, -67, -25, 55, -75, 407, 463, -35, -77, -37, -31, -19, 175, -81, 5, 77, -1
OFFSET
1,5
FORMULA
a(n) = A252748(A319630(n)).
PROG
(PARI)
A003961(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A252748(n) = (A003961(n) - (2*n));
is_A319630(n) = (1==gcd(n, A003961(n)));
k=0; n=0; while(k<200, n++; if(is_A319630(n), print1(A252748(n), ", ")));
CROSSREFS
Cf. also A379230.
Sequence in context: A262528 A359685 A362154 * A073106 A309692 A107229
KEYWORD
sign
AUTHOR
Antti Karttunen, Dec 23 2024
STATUS
approved