The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A173109 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A173109

Row sums of triangle A173108.
(history; published version)

#26 by Alois P. Heinz at Fri Apr 22 09:12:17 EDT 2022

STATUS

proposed

approved

#25 by Jean-François Alcover at Fri Apr 22 09:11:24 EDT 2022

STATUS

editing

proposed

#24 by Jean-François Alcover at Fri Apr 22 09:11:20 EDT 2022

MATHEMATICA

a[n_] := Sum[BellB[n-2k], {k, 0, Quotient[n, 2]}];

Table[a[n], {n, 0, 25}] (* Jean-François Alcover, Apr 22 2022 *)

STATUS

approved

editing

#23 by Alois P. Heinz at Thu Jun 17 16:32:15 EDT 2021

STATUS

editing

approved

#22 by Alois P. Heinz at Thu Jun 17 16:32:12 EDT 2021

EXAMPLE

a(5) = 58 = 52 + 5 + 1.

#21 by Alois P. Heinz at Thu Jun 17 16:31:54 EDT 2021

EXTENSIONS

Added more More terms, _ from _Sergei N. Gladkovskii_, Jan 04 2013

#20 by Alois P. Heinz at Thu Jun 17 16:31:34 EDT 2021

MAPLE

ab:= proc(n) option remember; add`if`(n=0, 1,

combinat[bell]add(b(n-2j)*kbinomial(n-1, j-1), kj=01..iquo(n, 2))

a:= n-> add(b(n-2*k), k=0..iquo(n, 2)):

#19 by Alois P. Heinz at Thu Jun 17 16:30:28 EDT 2021

LINKS

Alois P. Heinz, <a href="/A173109/b173109.txt">Table of n, a(n) for n = 0..576</a>

#18 by Alois P. Heinz at Thu Jun 17 16:17:50 EDT 2021

FORMULA

a(n) = Sum_{k=0..floor(n/2)} A000110(n-2*k). - Alois P. Heinz, Jun 17 2021

#17 by Alois P. Heinz at Thu Jun 17 16:16:45 EDT 2021

MAPLE

a:= proc(n) option remember; add(

combinat[bell](n-2*k), k=0..iquo(n, 2))

end:

seq(a(n), n=0..25); # Alois P. Heinz, Jun 17 2021

CROSSREFS

Cf. A000110, A087650, A173108.

STATUS

approved

editing