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A211707 Rectangular array:  R(n,k)=n+[n/2+1/2]+...+[n/k+1/2], where [ ]=floor and k>=1, by antidiagonals. 0
1, 2, 2, 3, 3, 2, 4, 5, 4, 2, 5, 6, 6, 5, 2, 6, 8, 7, 7, 5, 2, 7, 9, 10, 8, 8, 5, 2, 8, 11, 11, 11, 9, 9, 5, 2, 9, 12, 13, 13, 12, 10, 9, 5, 2, 10, 14, 15, 15, 14, 13, 11, 9, 5, 2, 11, 15, 17, 17, 16, 15, 14, 12, 9, 5, 2, 12, 17, 18, 19, 19, 17, 16, 15, 12, 9, 5, 2, 13, 18, 21 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Limit of n-th row:  A056549=(2,5,9,12,17,21,25,...).

Row 1:  A000027

Row 2:  A007494

R(n,n)=A077024(n)

For n>=1, row n is a homogeneous linear recurrence sequence of order A005728(n) with palindromic recurrence coefficients in the sense described at A211701.

LINKS

Table of n, a(n) for n=1..81.

EXAMPLE

Northwest corner:

1...2...3...4...5....6....7

2...3...5...6...8....9....11

2...4...6...7...10...11...12

2...5...7...8...11...13...15

2...5...8...9...12...14...16

MATHEMATICA

f[n_, m_] := Sum[Floor[n/k + 1/2], {k, 1, m}]

TableForm[Table[f[n, m], {m, 1, 20}, {n, 1, 16}]]

CROSSREFS

Cf. A211701

Sequence in context: A327487 A105496 A167618 * A303363 A045796 A127684

Adjacent sequences:  A211704 A211705 A211706 * A211708 A211709 A211710

KEYWORD

nonn,tabl

AUTHOR

Clark Kimberling, Apr 20 2012

STATUS

approved

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Last modified June 7 02:48 EDT 2020. Contains 334836 sequences. (Running on oeis4.)