A372608 - OEIS

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A372608

a(n) = Sum_{k=1..n} phi(n*k).

2

1, 3, 10, 18, 44, 40, 114, 124, 198, 192, 430, 292, 708, 540, 704, 888, 1552, 954, 2178, 1456, 1980, 2080, 3806, 2216, 4220, 3480, 4734, 4056, 7588, 3560, 9270, 6960, 7920, 7840, 9936, 7296, 15588, 10980, 13056, 11120, 21240, 10128, 24570, 16360, 17880, 19360, 32062

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Totient Function.

FORMULA

a(n) = A372606(n,n).

a(n) = A000010(n) * A070639(n).

PROG

(PARI) a(n) = sum(k=1, n, eulerphi(k*n));

CROSSREFS

Main diagonal of A372606.

Cf. A000010, A070639.

Sequence in context: A210286 A275988 A177955 * A298976 A265487 A074893

Adjacent sequences: A372605 A372606 A372607 * A372609 A372610 A372611

KEYWORD

nonn

AUTHOR

Seiichi Manyama, May 07 2024

STATUS

approved