A337544 - OEIS

A337544

a(n) = 2*phi(A003961(n)) - A003961(n).

1, 1, 3, 3, 5, 1, 9, 9, 15, 3, 11, 3, 15, 7, 13, 27, 17, 5, 21, 9, 25, 9, 27, 9, 35, 13, 75, 21, 29, -9, 35, 81, 31, 15, 43, 15, 39, 19, 43, 27, 41, -5, 45, 27, 65, 25, 51, 27, 99, 21, 49, 39, 57, 25, 53, 63, 61, 27, 59, -27, 65, 33, 125, 243, 73, -3, 69, 45, 79, 9, 71, 45, 77, 37, 91, 57, 97, 1, 81, 81, 375, 39, 87, -15, 83

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OFFSET

1,3

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..16384

Index entries for sequences computed from indices in prime factorization

FORMULA

a(n) = A083254(A003961(n)).

a(n) = 2*A003972(n) - A003961(n).

PROG

(PARI)

A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f);