A257883 -id:A257883 - cp's OEIS frontend

A175498 a(1)=1. a(n) = the smallest positive integer not occurring earlier such that a(n)-a(n-1) doesn't equal a(k)-a(k-1) for any k with 2 <= k <= n-1.

1, 2, 4, 3, 6, 10, 5, 11, 7, 12, 9, 16, 8, 17, 15, 23, 13, 24, 18, 28, 14, 26, 19, 32, 20, 34, 21, 36, 25, 41, 22, 39, 30, 48, 27, 46, 29, 49, 31, 52, 37, 59, 33, 56, 40, 64, 35, 60, 38, 65, 42, 68, 43, 71, 44, 73, 45, 75, 51, 82, 47, 79, 112, 50, 84, 53, 88, 54, 90, 57, 94, 55, 93, 61, 100, 58, 98, 62, 103, 63, 105, 67

Offset: 1

Leroy Quet, May 31 2010

This sequence is a permutation of the positive integers.
a(n+1)-a(n) = A175499(n).
Conjecture: the lexicographically earliest permutation of {1,2,...n} for which differences of adjacent numbers are all distinct (cf. A131529) has, for n-->infinity, this sequence as its prefix. - Joerg Arndt, May 27 2012

Joerg Arndt and Reinhard Zumkeller, Table of n, a(n) for n = 1..10000, first 1122 terms from Joerg Arndt
Index entries for sequences that are permutations of the natural numbers

Cf. A081145, A175499, A257465 (inverse), A257883, A131388, A131389, A257705.

import Data.List (delete)
a175498 n = a175498_list !! (n-1)
a175498_list = 1 : f 1 [2..] [] where
   f x zs ds = g zs where
     g (y:ys) | diff `elem` ds = g ys
              | otherwise      = y : f y (delete y zs) (diff:ds)
              where diff = y - x
-- Reinhard Zumkeller, Apr 25 2015

a[1] = 1; d[1] = 0; k = 1; z = 10000; zz = 120;
A[k_] := Table[a[i], {i, 1, k}]; diff[k_] := Table[d[i], {i, 1, k}];
c[k_] := Complement[Range[-z, z], diff[k]];
T[k_] := -a[k] + Complement[Range[z], A[k]];
Table[{h = Min[Intersection[c[k], T[k]]], a[k + 1] = a[k] + h, d[k + 1] = h, k = k + 1}, {i, 1, zz}];
u = Table[a[k], {k, 1, zz}]  (* Clark Kimberling, May 13 2015 *)

A175498_list, l, s, b1, b2 = [1,2], 2, 3, set(), set([1])
for n in range(3, 10**5):
    i = s
    while True:
        if not (i in b1 or i-l in b2):
            A175498_list.append(i)
            b1.add(i)
            b2.add(i-l)
            l = i
            while s in b1:
                b1.remove(s)
                s += 1
            break
        i += 1 # Chai Wah Wu, Dec 15 2014

More terms from Sean A. Irvine, Jan 27 2011

A257705 Sequence (a(n)) generated by Rule 1 (in Comments) with a(1) = 0 and d(1) = 0.

Original entry on oeis.org

0, 1, 3, 2, 5, 9, 7, 4, 10, 6, 11, 18, 13, 21, 15, 8, 17, 27, 19, 30, 20, 32, 23, 12, 25, 39, 26, 14, 29, 45, 31, 16, 33, 51, 35, 54, 37, 57, 38, 59, 41, 63, 43, 22, 46, 24, 47, 72, 49, 75, 50, 77, 53, 81, 55, 28, 58, 87, 56, 88, 60, 91, 62, 95, 65, 99, 67

Offset: 1

Clark Kimberling, May 12 2015

Rule 1 follows.  For k >= 1, let  A(k) = {a(1), …, a(k)} and D(k) = {d(1), …, d(k)}.  Begin with k = 1 and nonnegative integers a(1) and d(1).
Step 1:   If there is an integer h such that 1 - a(k) < h < 0 and h is not in D(k) and a(k) + h is not in A(k), let d(k+1) be the greatest such h, let a(k+1) = a(k) + h, replace k by k + 1, and repeat Step 1; otherwise do Step 2.
Step 2:  Let h be the least positive integer not in D(k) such that a(k) + h is not in A(k).  Let a(k+1) = a(k) + h and d(k+1) = h.  Replace k by k+1 and do Step 1.
Conjecture:  if a(1) is an nonnegative integer and d(1) is an integer, then (a(n)) is a permutation of the nonnegative integers (if a(1) = 0) or a permutation of the positive integers (if a(1) > 0).  Moreover, (d(n)) is a permutation of the integers if d(1) = 0, or of the nonzero integers if d(1) > 0.
Guide to related sequences:
a(1)  d(1)      (a(n))             (d(n))
0       0      A257705      A131389 except for initial terms
0       1      A257706      A131389 except for initial terms
0       2      A257876      A131389 except for initial terms
0       3      A257877      A257915
1       0      A131388      A131389
1       1      A257878      A131389 except for initial terms
2       0      A257879      A257880
2       1      A257881      A257880 except for initial terms
2       2      A257882      A257918

			a(2) = a(1) + d(2) = 0 + 1 = 1;
a(3) = a(2) + d(3) = 1 + 2 = 3;
a(4) = a(3) + d(4) = 3 + (-1) = 2.

Clark Kimberling, Table of n, a(n) for n = 1..1000

Cf. A131388, A081145, A257883, A175498.

a[1] = 0; d[1] = 0; k = 1; z = 10000; zz = 120;
A[k_] := Table[a[i], {i, 1, k}]; diff[k_] := Table[d[i], {i, 1, k}];
c[k_] := Complement[Range[-z, z], diff[k]];
T[k_] := -a[k] + Complement[Range[z], A[k]];
s[k_] := Intersection[Range[-a[k], -1], c[k], T[k]];
Table[If[Length[s[k]] == 0, {h = Min[Intersection[c[k], T[k]]], a[k + 1] = a[k] + h, d[k + 1] = h, k = k + 1}, {h = Max[s[k]], a[k + 1] = a[k] + h, d[k + 1] = h, k = k + 1}], {i, 1, zz}];
u = Table[a[k], {k, 1, zz}] (* A257705 *)
Table[d[k], {k, 1, zz}]     (* A131389 *)

a(k+1) - a(k) = d(k+1) for k >= 1.

Also, a(k) = A131388(n)-1.

A257905 Sequence (a(n)) generated by Rule 3 (in Comments) with a(1) = 0 and d(1) = 0.

Original entry on oeis.org

0, 1, 3, 2, 5, 11, 4, 9, 6, 13, 7, 15, 10, 8, 17, 35, 12, 25, 14, 29, 16, 33, 18, 37, 19, 39, 20, 41, 21, 43, 22, 45, 23, 47, 30, 26, 53, 24, 49, 40, 28, 57, 27, 55, 31, 63, 32, 65, 38, 42, 34, 69, 36, 73, 48, 97, 44, 89, 46, 93, 51, 103, 52, 105, 50, 101

Offset: 1

Clark Kimberling, May 16 2015

Rule 3 follows.  For k >= 1, let  A(k) = {a(1), …, a(k)} and D(k) = {d(1), …, d(k)}.  Begin with k = 1 and nonnegative integers a(1) and d(1).
Step 1:   If there is an integer h such that 1 - a(k) < h < 0 and h is not in D(k) and a(k) + h is not in A(k), let d(k+1) be the least such h, let a(k+1) = a(k) + h, replace k by k + 1, and repeat Step 1; otherwise do Step 2.
Step 2:  Let h be the least positive integer not in D(k) such that a(k) - h is not in A(k).  Let a(k+1) = a(k) + h and d(k+1) = h.  Replace k by k+1 and do Step 1.
Conjecture:  suppose that a(1) is an nonnegative integer and d(1) is an integer.
If a(1) = 0 and d(1) != 1, then (a(n)) is a permutation of the nonnegative integers;
if a(1) = 0 and d(1) = 1, then (a(n)) is a permutation of the nonnegative integers excluding 1;
if a(1) = 1, then (a(n)) is a permutation of the positive integers;
if a(1) > 1, then (a(n)) is a permutation of the integers >1;
if d(1) = 0, then (d(n)) is a permutation of the integers;
if d(1) !=0, then (d(n)) is a permutation of the nonzero integers.
Guide to related sequences:
a(1)  d(1)      (a(n))       (d(n))
0       0      A257905      A258047
0       1      A257906      A257907
0       2      A257908      A257909
0       3      A257910      A257980
1       0      A258046      A258047
1       1      A257981      A257982
1       2      A257983      A257909
2       0      A257985      A257047
2       1      A257986      A257982
2       2      A257987      A257909

			a(1) = 0, d(1) = 0;
a(2) = 1, d(2) = 1;
a(3) = 3, d(3) = 2;
a(4) = 2, d(4) = -1.

Clark Kimberling, Table of n, a(n) for n = 1..1000

Cf. A258047, A257705, A257883, A175498.

Cf. A256283 (putative inverse).

import Data.List ((\\))
a257905 n = a257905_list !! (n-1)
a257905_list = 0 : f [0] [0] where
   f xs@(x:_) ds = g [2 - x .. -1] where
     g [] = y : f (y:xs) (h:ds) where
                  y = x + h
                  (h:_) = [z | z <- [1..] \\ ds, x - z `notElem` xs]
     g (h:hs) | h `notElem` ds && y `notElem` xs = y : f (y:xs) (h:ds)
              | otherwise = g hs
              where y = x + h
-- Reinhard Zumkeller, Jun 03 2015

{a, f} = {{0}, {0}}; Do[tmp = {#, # - Last[a]} &[Min[Complement[#, Intersection[a, #]]&[Last[a] + Complement[#, Intersection[f, #]] &[Range[2 - Last[a], -1]]]]];
If[! IntegerQ[tmp[[1]]], tmp = {Last[a] + #, #} &[NestWhile[# + 1 &, 1, ! (! MemberQ[f, #] && ! MemberQ[a, Last[a] - #]) &]]]; AppendTo[a, tmp[[1]]]; AppendTo[f, tmp[[2]]], {120}]; {a, f} (* Peter J. C. Moses, May 14 2015 *)

a(n) = A258046(n) - 1 for n >= 1.

A257706 Sequence (a(n)) generated by Rule 1 (in Comments) with a(1) = 0 and d(1) = 1.

Original entry on oeis.org

0, 2, 1, 4, 8, 6, 3, 9, 5, 10, 17, 12, 20, 14, 7, 16, 26, 18, 29, 19, 31, 22, 11, 24, 38, 25, 13, 28, 44, 30, 15, 32, 50, 34, 53, 36, 56, 37, 58, 40, 62, 42, 21, 45, 23, 46, 71, 48, 74, 49, 76, 52, 80, 54, 27, 57, 86, 55, 87, 59, 90, 61, 94, 64, 98, 66, 33

Offset: 1

Clark Kimberling, May 12 2015

Rule 1 follows.  For k >= 1, let  A(k) = {a(1),..., a(k)} and D(k) = {d(1),..., d(k)}.  Begin with k = 1 and nonnegative integers a(1) and d(1).
Step 1:   If there is an integer h such that 1 - a(k) < h < 0 and h is not in D(k) and a(k) + h is not in A(k), let d(k+1) be the greatest such h, let a(k+1) = a(k) + h, replace k by k + 1, and repeat Step 1; otherwise do Step 2.
Step 2:  Let h be the least positive integer not in D(k) such that a(k) + h is not in A(k).  Let a(k+1) = a(k) + h and d(k+1) = h.  Replace k by k+1 and do Step 1.
Conjecture:  if a(1) is an nonnegative integer and d(1) is an integer, then (a(n)) is a permutation of the nonnegative integers (if a(1) = 0) or a permutation of the positive integers (if a(1) > 0).  Moreover, (d(n)) is a permutation of the integers if d(1) = 0, or of the nonzero integers if d(1) > 0.
See A257705 for a guide to related sequences.

			a(1) = 0, d(1) = 1;
a(2) = 2, d(2) = 2;
a(3) = 1, d(3) = -1;
a(4) = 4, d(4) = 3;
(The sequence d differs from A131389 only in the first 13 terms.)

Clark Kimberling, Table of n, a(n) for n = 1..1000

Cf. A131388, A257705, A081145, A257883, A175498.

a[1] = 0; d[1] = 1; k = 1; z = 10000; zz = 120;
A[k_] := Table[a[i], {i, 1, k}]; diff[k_] := Table[d[i], {i, 1, k}];
c[k_] := Complement[Range[-z, z], diff[k]];
T[k_] := -a[k] + Complement[Range[z], A[k]];
s[k_] := Intersection[Range[-a[k], -1], c[k], T[k]];
Table[If[Length[s[k]] == 0, {h = Min[Intersection[c[k], T[k]]], a[k + 1] = a[k] + h, d[k + 1] = h, k = k + 1}, {h = Max[s[k]], a[k + 1] = a[k] + h, d[k + 1] = h, k = k + 1}], {i, 1, zz}];
u = Table[a[k], {k, 1, zz}]  (* A257706 *)
Table[d[k], {k, 1, zz}]  (* A131389 shifted *)

a(n+1) - a(n) = d(n+1) = A131389(n+1) for n >= 1.

A257880 Sequence (d(n)) generated by Rule 1 (in Comments) with a(1) = 2 and d(1) = 0.

Original entry on oeis.org

0, -1, 2, 1, 3, -2, 4, -3, 5, 6, -4, -5, 7, 8, -7, -6, 9, 10, -8, -9, 12, -10, 11, 13, -11, 14, -13, 15, -12, 16, -14, -15, 17, 18, -16, -17, 19, 20, -19, -18, 22, 21, -20, 23, -22, 24, -21, -23, 25, 26, -25, 27, -24, 28, -26, -27, 30, -28, 29, 31, -29, 32

Offset: 1

Clark Kimberling, May 13 2015

This is the sequence (d(n)) of differences associated with the sequence a = A257879.
Rule 1 follows.  For k >= 1, let  A(k) = {a(1), …, a(k)} and D(k) = {d(1), …, d(k)}.  Begin with k = 1 and nonnegative integers a(1) and d(1).
Step 1:   If there is an integer h such that 1 - a(k) < h < 0 and h is not in D(k) and a(k) + h is not in A(k), let d(k+1) be the greatest such h, let a(k+1) = a(k) + h, replace k by k + 1, and repeat Step 1; otherwise do Step 2.
Step 2:  Let h be the least positive integer not in D(k) such that a(k) + h is not in A(k).  Let a(k+1) = a(k) + h and d(k+1) = h.  Replace k by k+1 and do Step 1.
Conjecture:  if a(1) is an nonnegative integer and d(1) is an integer, then (a(n)) is a permutation of the nonnegative integers (if a(1) = 0) or a permutation of the positive integers (if a(1) > 0).  Moreover, (d(n)) is a permutation of the integers if d(1) = 0, or of the nonzero integers if d(1) > 0.
See A257705 for a guide to related sequences.

			a(1) = 2, d(1) = 0;
a(2) = 1, d(2) = -1;
a(3) = 3, d(3) = 2;
a(4) = 4, d(4) = 1.

Clark Kimberling, Table of n, a(n) for n = 1..1000

Cf. A131389, A257705, A081145, A257883, A175499.

a[1] = 2; d[1] = 0; k = 1; z = 10000; zz = 120;
A[k_] := Table[a[i], {i, 1, k}]; diff[k_] := Table[d[i], {i, 1, k}];
c[k_] := Complement[Range[-z, z], diff[k]];
T[k_] := -a[k] + Complement[Range[z], A[k]];
s[k_] := Intersection[Range[-a[k], -1], c[k], T[k]];
Table[If[Length[s[k]] == 0, {h = Min[Intersection[c[k], T[k]]], a[k + 1] = a[k] + h, d[k + 1] = h, k = k + 1}, {h = Max[s[k]], a[k + 1] = a[k] + h, d[k + 1] = h, k = k + 1}], {i, 1, zz}];
u = Table[a[k], {k, 1, zz}] (* A257879 *)
Table[d[k], {k, 1, zz}]     (* A257880 *)

d(k) = a(k) - a(k-1) for k >=2, where a(k) = A257877(k).

A257877 Sequence (a(n)) generated by Rule 1 (in Comments) with a(1) = 0 and d(1) = 3.

Original entry on oeis.org

0, 1, 3, 2, 6, 4, 9, 5, 11, 8, 15, 10, 18, 12, 21, 14, 24, 16, 7, 19, 30, 20, 33, 22, 36, 23, 38, 26, 42, 28, 13, 31, 48, 32, 51, 34, 54, 35, 17, 39, 60, 40, 63, 41, 65, 44, 69, 46, 72, 47, 74, 50, 78, 52, 25, 55, 27, 56, 87, 58, 90, 59, 29, 62, 96, 64, 99

Offset: 1

Clark Kimberling, May 12 2015

Rule 1 follows.  For k >= 1, let  A(k) = {a(1), …, a(k)} and D(k) = {d(1), …, d(k)}.  Begin with k = 1 and nonnegative integers a(1) and d(1).
Step 1:   If there is an integer h such that 1 - a(k) < h < 0 and h is not in D(k) and a(k) + h is not in A(k), let d(k+1) be the greatest such h, let a(k+1) = a(k) + h, replace k by k + 1, and repeat Step 1; otherwise do Step 2.
Step 2:  Let h be the least positive integer not in D(k) such that a(k) + h is not in A(k).  Let a(k+1) = a(k) + h and d(k+1) = h.  Replace k by k+1 and do Step 1.
Conjecture:  if a(1) is an nonnegative integer and d(1) is an integer, then (a(n)) is a permutation of the nonnegative integers (if a(1) = 0) or a permutation of the positive integers (if a(1) > 0).  Moreover, (d(n)) is a permutation of the integers if d(1) = 0, or of the nonzero integers if d(1) > 0.
See A257705 for a guide to related sequences.

			a(1) = 0, d(1) = 3;
a(2) = 1, d(2) = 1;
a(3) = 3, d(3) = 2;
a(4) = 2, d(4) = -1.

Clark Kimberling, Table of n, a(n) for n = 1..1000

Cf. A131388, A257915, A257705, A081145, A257883, A175498.

a[1] = 0; d[1] = 3; k = 1; z = 10000; zz = 120;
A[k_] := Table[a[i], {i, 1, k}]; diff[k_] := Table[d[i], {i, 1, k}];
c[k_] := Complement[Range[-z, z], diff[k]];
T[k_] := -a[k] + Complement[Range[z], A[k]];
s[k_] := Intersection[Range[-a[k], -1], c[k], T[k]];
Table[If[Length[s[k]] == 0, {h = Min[Intersection[c[k], T[k]]], a[k + 1] = a[k] + h, d[k + 1] = h, k = k + 1}, {h = Max[s[k]], a[k + 1] = a[k] + h, d[k + 1] = h, k = k + 1}], {i, 1, zz}];
u = Table[a[k], {k, 1, zz}]  (* A257877 *)
Table[d[k], {k, 1, zz}]  (* A257915 *)

a(k+1) - a(k) = d(k+1) for k >= 1.

A257879 Sequence (a(n)) generated by Rule 1 (in Comments) with a(1) = 2 and d(1) = 0.

Original entry on oeis.org

2, 1, 3, 4, 7, 5, 9, 6, 11, 17, 13, 8, 15, 23, 16, 10, 19, 29, 21, 12, 24, 14, 25, 38, 27, 41, 28, 43, 31, 47, 33, 18, 35, 53, 37, 20, 39, 59, 40, 22, 44, 65, 45, 68, 46, 70, 49, 26, 51, 77, 52, 79, 55, 83, 57, 30, 60, 32, 61, 92, 63, 95, 64, 34, 67, 101, 69

Offset: 1

Clark Kimberling, May 12 2015

Rule 1 follows.  For k >= 1, let  A(k) = {a(1), …, a(k)} and D(k) = {d(1), …, d(k)}.  Begin with k = 1 and nonnegative integers a(1) and d(1).
Step 1:   If there is an integer h such that 1 - a(k) < h < 0 and h is not in D(k) and a(k) + h is not in A(k), let d(k+1) be the greatest such h, let a(k+1) = a(k) + h, replace k by k + 1, and repeat Step 1; otherwise do Step 2.
Step 2:  Let h be the least positive integer not in D(k) such that a(k) + h is not in A(k).  Let a(k+1) = a(k) + h and d(k+1) = h.  Replace k by k+1 and do Step 1.
Conjecture:  if a(1) is an nonnegative integer and d(1) is an integer, then (a(n)) is a permutation of the nonnegative integers (if a(1) = 0) or a permutation of the positive integers (if a(1) > 0).  Moreover, (d(n)) is a permutation of the integers if d(1) = 0, or of the nonzero integers if d(1) > 0.
See A257705 for a guide to related sequences.

			a(1) = 2, d(1) = 0;
a(2) = 1, d(2) = -1;
a(3) = 3, d(3) = 2;
a(4) = 4, d(4) = 1.

Clark Kimberling, Table of n, a(n) for n = 1..1000

Cf. A131388, A131389, A257705, A081145, A257883, A175498.

a[1] = 2; d[1] = 0; k = 1; z = 10000; zz = 120;
A[k_] := Table[a[i], {i, 1, k}]; diff[k_] := Table[d[i], {i, 1, k}];
c[k_] := Complement[Range[-z, z], diff[k]];
T[k_] := -a[k] + Complement[Range[z], A[k]];
s[k_] := Intersection[Range[-a[k], -1], c[k], T[k]];
Table[If[Length[s[k]] == 0, {h = Min[Intersection[c[k], T[k]]], a[k + 1] = a[k] + h, d[k + 1] = h, k = k + 1}, {h = Max[s[k]], a[k + 1] = a[k] + h, d[k + 1] = h, k = k + 1}], {i, 1, zz}];
u = Table[a[k], {k, 1, zz}]  (* A257879 *)
Table[d[k], {k, 1, zz}]  (* A257880 *)

a(k+1) - a(k) = d(k+1) for k >= 1.

A257882 Sequence (a(n)) generated by Rule 1 (in Comments) with a(1) = 2 and d(1) = 2.

Original entry on oeis.org

2, 1, 4, 5, 3, 7, 12, 9, 15, 11, 6, 13, 21, 14, 8, 17, 27, 19, 10, 22, 33, 23, 36, 25, 39, 26, 41, 29, 45, 31, 16, 34, 18, 35, 54, 37, 57, 38, 20, 42, 63, 43, 66, 44, 68, 47, 24, 49, 75, 51, 78, 53, 81, 55, 28, 58, 30, 59, 90, 61, 93, 62, 32, 65, 99, 67, 102

Offset: 1

Clark Kimberling, May 13 2015

Rule 1 follows.  For k >= 1, let  A(k) = {a(1), …, a(k)} and D(k) = {d(1), …, d(k)}.  Begin with k = 1 and nonnegative integers a(1) and d(1).
Step 1:   If there is an integer h such that 1 - a(k) < h < 0 and h is not in D(k) and a(k) + h is not in A(k), let d(k+1) be the greatest such h, let a(k+1) = a(k) + h, replace k by k + 1, and repeat Step 1; otherwise do Step 2.
Step 2:  Let h be the least positive integer not in D(k) such that a(k) + h is not in A(k).  Let a(k+1) = a(k) + h and d(k+1) = h.  Replace k by k+1 and do Step 1.
Conjecture:  if a(1) is an nonnegative integer and d(1) is an integer, then (a(n)) is a permutation of the nonnegative integers (if a(1) = 0) or a permutation of the positive integers (if a(1) > 0).  Moreover, (d(n)) is a permutation of the integers if d(1) = 0, or of the nonzero integers if d(1) > 0.
See A257705 for a guide to related sequences.

			a(1) = 2, d(1) = 2;
a(2) = 1, d(2) = -1;
a(3) = 4, d(3) = 3;
a(4) = 5, d(4) = 1.

Clark Kimberling, Table of n, a(n) for n = 1..1000

Cf. A257918, A257880, A257705, A081145, A257883, A175498.

a[1] = 2; d[1] = 2; k = 1; z = 10000; zz = 120;
A[k_] := Table[a[i], {i, 1, k}]; diff[k_] := Table[d[i], {i, 1, k}];
c[k_] := Complement[Range[-z, z], diff[k]];
T[k_] := -a[k] + Complement[Range[z], A[k]];
s[k_] := Intersection[Range[-a[k], -1], c[k], T[k]];
Table[If[Length[s[k]] == 0, {h = Min[Intersection[c[k], T[k]]], a[k + 1] = a[k] + h, d[k + 1] = h, k = k + 1}, {h = Max[s[k]], a[k + 1] = a[k] + h, d[k + 1] = h, k = k + 1}], {i, 1, zz}];
u = Table[a[k], {k, 1, zz}]  (* A257882 *)
Table[d[k], {k, 1, zz}]  (* A257918 *)

a(k+1) - a(k) = d(k+1) for k >= 1.

A257884 Sequence (a(n)) generated by Algorithm (in Comments) with a(1) = 0 and d(1) = 1.

Original entry on oeis.org

0, 2, 1, 4, 8, 3, 9, 5, 10, 7, 14, 6, 15, 13, 21, 11, 22, 16, 26, 12, 24, 17, 30, 18, 32, 19, 34, 23, 39, 20, 37, 28, 46, 25, 44, 27, 47, 29, 50, 35, 57, 31, 54, 38, 62, 33, 58, 36, 63, 40, 66, 41, 69, 42, 71, 43, 73, 49, 80, 45, 77, 110, 48, 82, 51, 86, 52

Offset: 1

Clark Kimberling, May 13 2015

Algorithm:  For k >= 1, let  A(k) = {a(1), …, a(k)} and D(k) = {d(1), …, d(k)}.  Begin with k = 1 and nonnegative integers a(1) and d(1).  Let h be the least integer > -a(k) such that h is not in D(k) and a(k) + h is not in A(k).  Let a(k+1) = a(k) + h and d(k+1) = h.  Replace k by k+1 and repeat inductively.
Conjecture:  if a(1) is an nonnegative integer and d(1) is an integer, then (a(n)) is a permutation of the nonnegative integers (if a(1) = 0) or a permutation of the positive integers (if a(1) > 0).  Moreover, (d(n)) is a permutation of the integers if d(1) = 0, or of the nonzero integers if d(1) > 0.
See A257883 for a guide to related sequences.

			a(1) = 0, d(1) = 1;
a(2) = 2, d(2) = 2;
a(3) = 1, d(3) = -1;
a(4) = 4, d(4) = 3.

Clark Kimberling, Table of n, a(n) for n = 1..1000

Cf. A257883, A175498, A257705, A081145.

a[1] = 0; d[1] = 1; k = 1; z = 10000; zz = 120;
A[k_] := Table[a[i], {i, 1, k}]; diff[k_] := Table[d[i], {i, 1, k}];
c[k_] := Complement[Range[-z, z], diff[k]];
T[k_] := -a[k] + Complement[Range[z], A[k]]
Table[{h = Min[Intersection[c[k], T[k]]], a[k + 1] = a[k] + h,
   d[k + 1] = h, k = k + 1}, {i, 1, zz}];
u = Table[a[k], {k, 1, zz}]  (* A257884 *)
Table[d[k], {k, 1, zz}]      (* A175499 *)

a(k+1) - a(k) = d(k+1) for k >= 1.

A257885 Sequence (a(n)) generated by Algorithm (in Comments) with a(1) = 0 and d(1) = 2.

Original entry on oeis.org

0, 1, 4, 2, 6, 3, 8, 7, 13, 5, 12, 20, 9, 18, 11, 21, 15, 10, 22, 33, 14, 27, 17, 31, 16, 32, 19, 34, 25, 42, 24, 43, 23, 41, 29, 49, 26, 47, 30, 52, 28, 51, 35, 59, 37, 62, 36, 63, 38, 64, 50, 46, 74, 39, 68, 40, 70, 101, 44, 76, 45, 78, 48, 82, 53, 88, 54

Offset: 1

Clark Kimberling, May 13 2015

Algorithm:  For k >= 1, let  A(k) = {a(1), …, a(k)} and D(k) = {d(1), …, d(k)}.  Begin with k = 1 and nonnegative integers a(1) and d(1).  Let h be the least integer > -a(k) such that h is not in D(k) and a(k) + h is not in A(k).  Let a(k+1) = a(k) + h and d(k+1) = h.  Replace k by k+1 and repeat inductively.
Conjecture:  if a(1) is an nonnegative integer and d(1) is an integer, then (a(n)) is a permutation of the nonnegative integers (if a(1) = 0) or a permutation of the positive integers (if a(1) > 0).  Moreover, (d(n)) is a permutation of the integers if d(1) = 0, or of the nonzero integers if d(1) > 0.
See A257883 for a guide to related sequences.

			a(1) = 0, d(1) = 2;
a(2) = 1, d(2) = 1;
a(3) = 4, d(3) = 3;
a(4) = 2, d(4) = -2.

Clark Kimberling, Table of n, a(n) for n = 1..1000

Cf. A257902, A257883, A257705.

a[1] = 0; d[1] = 2; k = 1; z = 10000; zz = 120;
A[k_] := Table[a[i], {i, 1, k}]; diff[k_] := Table[d[i], {i, 1, k}];
c[k_] := Complement[Range[-z, z], diff[k]];
T[k_] := -a[k] + Complement[Range[z], A[k]]
Table[{h = Min[Intersection[c[k], T[k]]], a[k + 1] = a[k] + h,
   d[k + 1] = h, k = k + 1}, {i, 1, zz}];
u = Table[a[k], {k, 1, zz}]  (* A257885 *)
Table[d[k], {k, 1, zz}] (* A257902 *)

a(k+1) - a(k) = d(k+1) for k >= 1.

cp's OEIS Frontend

A175498 a(1)=1. a(n) = the smallest positive integer not occurring earlier such that a(n)-a(n-1) doesn't equal a(k)-a(k-1) for any k with 2 <= k <= n-1.

Views

Author

Keywords

Comments

Links

Crossrefs

Programs

Haskell

Mathematica

Python

Extensions

A257705 Sequence (a(n)) generated by Rule 1 (in Comments) with a(1) = 0 and d(1) = 0.

Views

Author

Keywords

Comments

Examples

Links

Crossrefs

Programs

Mathematica

Formula

A257905 Sequence (a(n)) generated by Rule 3 (in Comments) with a(1) = 0 and d(1) = 0.

Views

Author

Keywords

Comments

Examples

Links

Crossrefs

Programs

Haskell

Mathematica

Formula

A257706 Sequence (a(n)) generated by Rule 1 (in Comments) with a(1) = 0 and d(1) = 1.

Views

Author

Keywords

Comments

Examples

Links

Crossrefs

Programs

Mathematica

Formula

A257880 Sequence (d(n)) generated by Rule 1 (in Comments) with a(1) = 2 and d(1) = 0.

Views

Author

Keywords

Comments

Examples

Links

Crossrefs

Programs

Mathematica

Formula

A257877 Sequence (a(n)) generated by Rule 1 (in Comments) with a(1) = 0 and d(1) = 3.

Views

Author

Keywords

Comments

Examples

Links

Crossrefs

Programs

Mathematica

Formula

A257879 Sequence (a(n)) generated by Rule 1 (in Comments) with a(1) = 2 and d(1) = 0.

Views

Author

Keywords

Comments

Examples

Links

Crossrefs

Programs

Mathematica

Formula