The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A185283 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A185283

Least k such that sigma(1) + sigma(2) + sigma(3) +...+ sigma(k) >= n.
(history; published version)

#21 by Harvey P. Dale at Sat Aug 29 19:58:18 EDT 2020

STATUS

editing

approved

#20 by Harvey P. Dale at Sat Aug 29 19:57:59 EDT 2020

MATHEMATICA

Module[{nn=10, ad, th}, ad={#[[1]], #[[2]]}&/@Partition[Accumulate[ DivisorSigma[ 1, Range[nn]]], 2, 1]; th=Thread[{Range[2, nn], ad}]; Join[ {0, 1}, Flatten[Table[#[[1]], #[[2, 2]]-#[[2, 1]]]&/@th]]] (* Harvey P. Dale, Aug 29 2020 *)

STATUS

approved

editing

#19 by OEIS Server at Thu Sep 12 12:55:24 EDT 2019

LINKS

Alois P. Heinz, <a href="/A185283/b185283_1.txt">Table of n, a(n) for n = 0..100000</a> (terms n = 1..1000 from G. C. Greubel)

#18 by Alois P. Heinz at Thu Sep 12 12:55:24 EDT 2019

STATUS

editing

approved

Discussion

Thu Sep 12

12:55

OEIS Server: Installed new b-file as b185283.txt.  Old b-file is now b185283_1.txt.

#17 by Alois P. Heinz at Thu Sep 12 12:55:05 EDT 2019

LINKS

Alois P. Heinz, <a href="/A185283/b185283_1.txt">Table of n, a(n) for n = 0..100000</a> (terms n = 1..1000 from G. C. Greubel)

#16 by Alois P. Heinz at Thu Sep 12 12:53:46 EDT 2019

LINKS

G. CAlois P. Greubel, Heinz, <a href="/A185283/b185283_1.txt">Table of n, a(n) for n = 10..1000100000</a>

#15 by Alois P. Heinz at Thu Sep 12 12:51:21 EDT 2019

MAPLE

b:= proc(n) option remember; `if`(n=0, 0,

numtheory[sigma](n)+b(n-1))

end:

a:= proc(n) option remember; local k; for k from

`if`(n=0, 0, a(n-1)) do if b(k)>=n then return k fi od

end:

seq(a(n), n=0..120); # Alois P. Heinz, Sep 12 2019

#14 by Alois P. Heinz at Thu Sep 12 12:47:55 EDT 2019

DATA

0, 1, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10

OFFSET

1,2

0,3

EXTENSIONS

a(0)=0 prepended by Alois P. Heinz, Sep 12 2019

Discussion

Thu Sep 12

12:49

Alois P. Heinz: a(0)=0 is important ... no sigma(0) evaluation (which is undefined) needed for that!

#13 by Alois P. Heinz at Thu Sep 12 12:45:09 EDT 2019

CROSSREFS

Cf. A000203, A024916.

STATUS

approved

editing

#12 by Michel Marcus at Mon Jun 26 01:15:19 EDT 2017

STATUS

reviewed

approved