A280246 -id:A280246 - cp's OEIS frontend

A280247 Partial sums of A280246 (Product_{d|n} psi(d)).

1, 2, 5, 9, 19, 37, 58, 122, 203, 403, 458, 2186, 2264, 3146, 4946, 9042, 9178, 35422, 35593, 99593, 107531, 113581, 113834, 2768042, 2770542, 2782710, 2802393, 3395097, 3395503, 29315503, 29315968, 30364544, 30418994, 30455986, 30544186, 574739770, 574740436

Offset: 1

Jaroslav Krizek, Dec 30 2016

nonn

psi(n) is the sum of totatives of n (A023896).

Cf. A023896, A280246, A280248.

[&+[&*[&+[h: h in [1..d] | GCD(h,d) eq 1]: d in Divisors(k)]: k in [1..n]]: n in [1..100]];

Accumulate@ Table[Product[Total@ Select[Range@ d, CoprimeQ[d, #] &], {d, Divisors@ n}], {n, 37}] (* Michael De Vlieger, Dec 30 2016 *)

a(n) = Sum_{i=1..n} A280246(i).

A280248 Partial products of A280246 (Product_{d|n} psi(d)).

Original entry on oeis.org

1, 1, 3, 12, 120, 2160, 45360, 2903040, 235146240, 47029248000, 2586608640000, 4469659729920000, 348633458933760000, 307494710779576320000, 553490479403237376000000, 2267097003635660292096000000, 308325192494449799725056000000

Offset: 1

Jaroslav Krizek, Dec 30 2016

nonn

psi(n) is the sum of totatives of n (A023896).

Cf. A023896, A280246, A280247.

[&*[&*[&+[h: h in [1..d] | GCD(h,d) eq 1]: d in Divisors(k)]: k in [1..n]]: n in [1..100]]

FoldList[#1 #2 &, Table[Product[Total@ Select[Range@ d, CoprimeQ[d, #] &], {d, Divisors@ n}], {n, 17}]] (* Michael De Vlieger, Dec 30 2016 *)

a(n) = Product_{i=1..n} A280246(i).

cp's OEIS Frontend

A280247 Partial sums of A280246 (Product_{d|n} psi(d)).

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