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A285121 Min(|d(k+1-i) - d(i)|, for i = 1..k, where d(1),..,d(k) are the divisors of n(n+1)(n+2)/6. 1
0, 0, 0, 0, 3, 1, 2, 1, 5, 2, 4, 9, 9, 12, 22, 8, 14, 10, 32, 8, 3, 9, 54, 2, 4, 2, 20, 11, 5, 12, 114, 18, 26, 20, 8, 1, 31, 35, 210, 9, 48, 58, 244, 68, 19, 17, 26, 90, 90, 0, 56, 40, 115, 3, 6, 3, 36, 51, 492, 91, 173, 89, 34, 25, 2, 12, 192, 81, 257, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

Clark Kimberling, Table of n, a(n) for n = 1..10000

FORMULA

a(n)=A056737(A000292(n)).

EXAMPLE

6(6+1)(6+2)/6 = 56 has divisors 1,2,4,7,8,14,28,56, so that k=8 and d(k+1-i) - d(i) ranges through {-55, -26, -10, -1, 1, 10, 26, 55}, so that a(6) = 1.

MATHEMATICA

f[n_] := f[n] = n(n+1)(n+2)/6;

Table[Divisors[f[n]] - Reverse[Divisors[f[n]]], {n, 1, 10}]

Table[Min[Abs[Divisors[f[n]] - Reverse[Divisors[f[n]]]]], {n, 1, 100}]

CROSSREFS

Cf. A000292, A002378, A056737.

Sequence in context: A059807 A214208 A279965 * A295935 A318323 A135261

Adjacent sequences:  A285118 A285119 A285120 * A285122 A285123 A285124

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling, Apr 11 2017

STATUS

approved

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Last modified August 13 02:09 EDT 2020. Contains 336441 sequences. (Running on oeis4.)