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A053783 (1+e)-harmonic numbers: harmonic mean of (1+e)-divisors is integral. 1
1, 6, 28, 140, 728, 1638, 2184, 3640, 8008, 8190, 10920, 18620, 23808, 23895, 27846, 37128, 47790, 55860, 69160, 148960, 166656, 189810, 237510, 242060, 316680, 334530, 359600, 406215, 446880, 484120, 525690, 669060, 726180, 1029952 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

If n = Product p(i)^r(i), d = Product p(i)^s(i) and s(i) = 0 or s(i) divides r(i), then d is a (1+e)-divisor of n.

LINKS

Table of n, a(n) for n=1..34.

CROSSREFS

Cf. A001599, A049599, A051378.

Sequence in context: A199315 A001599 A074247 * A216383 A110047 A163029

Adjacent sequences:  A053780 A053781 A053782 * A053784 A053785 A053786

KEYWORD

easy,nonn

AUTHOR

Naohiro Nomoto, Apr 14 2001

STATUS

approved

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Last modified May 19 07:18 EDT 2013. Contains 225429 sequences.