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Revision History for A205122 (Underlined text is an addition; strikethrough text is a deletion.)

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A205122 Least k such that n divides s(k)-s(j) for some j satisfying 1<=j<k, where s(j)=j*(2^(j-1)).
(history; published version)
#5 by Russ Cox at Fri Mar 30 18:58:10 EDT 2012
AUTHOR

_Clark Kimberling (ck6(AT)evansville.edu), _, Jan 25 2012

Discussion
Fri Mar 30 18:58
OEIS Server: https://oeis.org/edit/global/285
#4 by T. D. Noe at Wed Jan 25 18:25:44 EST 2012
STATUS

proposed

approved

#3 by Clark Kimberling at Wed Jan 25 18:01:09 EST 2012
STATUS

editing

proposed

#2 by Clark Kimberling at Wed Jan 25 14:12:58 EST 2012
NAME

allocatedLeast k such that n divides s(k)-s(j) for some j satisfying Clark1<=j<k, where Kimberlings(j)=j*(2^(j-1)).

DATA

2, 3, 2, 3, 4, 5, 4, 3, 6, 4, 3, 5, 7, 4, 6, 5, 5, 6, 5, 4, 10, 8, 7, 5, 9, 7, 11, 4, 9, 6, 4, 6, 8, 5, 10, 6, 7, 5, 11, 6, 13, 10, 16, 8, 6, 7, 6, 5, 9, 9, 8, 7, 10, 11, 13, 6, 14, 9, 8, 6, 16, 8, 10, 7, 17, 9, 15, 5, 12, 10

OFFSET

1,1

COMMENTS

See A204892 for a discussion and guide to related sequences.

MATHEMATICA

s[n_] := s[n] = n*2^(n - 1); z1 = 250; z2 = 70;

Table[s[n], {n, 1, 30}] (* A001787 *)

u[m_] := u[m] = Flatten[Table[s[k] - s[j], {k, 2, z1}, {j, 1, k - 1}]][[m]]

Table[u[m], {m, 1, z1}] (* A205120 *)

v[n_, h_] := v[n, h] = If[IntegerQ[u[h]/n], h, 0]

w[n_] := w[n] = Table[v[n, h], {h, 1, z1}]

d[n_] := d[n] = First[Delete[w[n], Position[w[n], 0]]]

Table[d[n], {n, 1, z2}] (* A205121 *)

k[n_] := k[n] = Floor[(3 + Sqrt[8 d[n] - 1])/2]

m[n_] := m[n] = Floor[(-1 + Sqrt[8 n - 7])/2]

j[n_] := j[n] = d[n] - m[d[n]] (m[d[n]] + 1)/2

Table[k[n], {n, 1, z2}] (* A205122 *)

Table[j[n], {n, 1, z2}] (* A205123 *)

Table[s[k[n]], {n, 1, z2}] (* A205124 *)

Table[s[j[n]], {n, 1, z2}] (* A205125 *)

Table[s[k[n]] - s[j[n]], {n, 1, z2}] (* A205126 *)

Table[(s[k[n]] - s[j[n]])/n, {n, 1, z2}] (* A205127 *)

CROSSREFS

Cf. A001787, A204892, A205127.

KEYWORD

allocated

nonn

AUTHOR

Clark Kimberling (ck6(AT)evansville.edu), Jan 25 2012

STATUS

approved

editing

#1 by Clark Kimberling at Sun Jan 22 10:30:44 EST 2012
NAME

allocated for Clark Kimberling

KEYWORD

allocated

STATUS

approved

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Last modified August 29 14:31 EDT 2024. Contains 375517 sequences. (Running on oeis4.)