A348508 a(n) = A003959(n) - 2*n, where A003959 is multiplicative with a(p^e) = (p+1)^e.

-1, -1, -2, 1, -4, 0, -6, 11, -2, -2, -10, 12, -12, -4, -6, 49, -16, 12, -18, 14, -10, -8, -22, 60, -14, -10, 10, 16, -28, 12, -30, 179, -18, -14, -22, 72, -36, -16, -22, 82, -40, 12, -42, 20, 6, -20, -46, 228, -34, 8, -30, 22, -52, 84, -38, 104, -34, -26, -58, 96, -60, -28, 2, 601, -46, 12, -66, 26, -42, 4, -70, 288

Offset

1,3

Links

Antti Karttunen, Table of n, a(n) for n = 1..20000

Formula

a(n) = A003959(n) - 2*n.

a(n) = A348507(n) - n.

a(n) = A348029(n) - A033879(n).

From Antti Karttunen, Dec 05 2021: (Start)

a(n) = A168036(n) + A348970(n).

For all n >= 1, a(A138636(n)) = 12.

(End)

a(p) = 1 - p if p prime. - Bernard Schott, Feb 17 2022

Mathematica

f[p_, e_] := (p + 1)^e; a[1] = -1; a[n_] := Times @@ f @@@ FactorInteger[n] - 2*n; Array[a, 100] (* Amiram Eldar, Oct 30 2021 *)

Prog

(PARI)
A003959(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1]++); factorback(f); };
A348508(n) = (A003959(n) - 2*n);

Crossrefs

Cf. A003959, A033879, A138636, A168036, A252748, A348029, A348970.

Sequence in context: A291200 A326143 A011017 * A077954 A077979 A297108

Adjacent sequences: A348505 A348506 A348507 * A348509 A348510 A348511

Keyword

sign

Author

Antti Karttunen, Oct 30 2021

Status

approved