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A276836 Denominator of modified von Mangoldt function defined recursively. 2
1, 1, 1, 1, 1, 2, 1, 3, 1, 4, 3, 5, 1, 6, 1, 7, 15, 2, 1, 9, 1, 5, 21, 11, 1, 2, 5, 13, 9, 7, 1, 15, 1, 8, 11, 17, 35, 27, 1, 19, 39, 5, 1, 7, 1, 44, 45, 69, 1, 54, 7, 125, 17, 39, 1, 27, 55, 14, 57, 116 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

COMMENTS

See A276835 for the conjecture about the ratio A276835(n)/A276836(n).

LINKS

Table of n, a(n) for n=1..60.

FORMULA

Recurrence for the ratio A276835(n)/A276836(n):

t(1, 1) = 1, t(n, k) = if(n/k = 2 then 2 else if(and(k == 1, n >= 3), n/(Product_{i = 1..n-1} t(n, k + i))/(Product_{i = 1..n-1} t(n, k + i)) else if(mod(n, k) = 0 then t(n/k, 1) else 1) else 1)).

MATHEMATICA

Clear[t]; nn = 60; t[1, 1] = 1; t[n_, k_] := t[n, k] = If[n/k == 2, 2, If[And[k == 1, n >= 3], n/Product[t[n, k + i], {i, 1, n - 1}]/Product[t[n - 2, k + i], {i, 1, n - 1}], If[Mod[n, k] == 0, t[n/k, 1], 1], 1]]; a = Table[t[n, 1], {n, 1, nn}]; Numerator[a]; Denominator[a]

CROSSREFS

Cf. A276835, A006512, A014963.

Sequence in context: A291326 A291325 A116512 * A291324 A075388 A036445

Adjacent sequences:  A276833 A276834 A276835 * A276837 A276838 A276839

KEYWORD

nonn,frac,more

AUTHOR

Mats Granvik, Sep 20 2016

STATUS

approved

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Last modified May 15 02:21 EDT 2021. Contains 343909 sequences. (Running on oeis4.)