

A275254


The biunitary gcdsum function.


2



1, 3, 5, 7, 9, 14, 13, 15, 17, 25, 21, 30, 25, 36, 43, 31, 33, 47, 37, 57, 61, 58, 45, 64, 49, 69, 53, 82, 57, 108, 61, 63, 99, 91, 113, 99, 73, 102, 117, 117, 81, 163, 85, 132, 141, 124, 93, 130, 97, 135, 155, 157, 105, 146, 181
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OFFSET

1,2


COMMENTS

Row sums of A165430.


LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000
L. Toth, On the BiUnitary Analogues of Euler's Arithmetical Function and the GcdSum Function, JIS 12 (2009) 09.5.2, function P**(n).


FORMULA

a(n) = Sum_{k=1..n} A165430(n,k).


MAPLE

Pstarstar := proc(n)
add(A165430(k, n), k=1..n) ;
end proc:


MATHEMATICA

phi[x_, n_] := Sum[Boole[GCD[k, n] == 1], {k, 1, x}]; uphi[1]=1; uphi[n_] := Times @@ (1 + Power @@@ FactorInteger[n]); a[n_] := DivisorSum[n, uphi[#] * phi[n/#, #] &, GCD[#, n/#] == 1 &]; Array[a, 100] (* Amiram Eldar, Sep 09 2019 *)


CROSSREFS

Cf. A165430.
Sequence in context: A107220 A249412 A098758 * A029608 A211135 A145388
Adjacent sequences: A275251 A275252 A275253 * A275255 A275256 A275257


KEYWORD

nonn


AUTHOR

R. J. Mathar, Jul 21 2016


STATUS

approved



