OFFSET
1,2
COMMENTS
Does every number appear in the sequence of absolute values (see A308007)?
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..5000
MATHEMATICA
f[s_] := Block[{k = 1, d = Abs[Most@s - Rest@s], l = Last@s}, While[MemberQ[s, k] || MemberQ[d, Abs[l - k]], k++ ]; Append[s, k]]; t = Nest[f, {1}, 75]; Rest@t - Most@t (* Robert G. Wilson v, Jun 13 2006 *)
PROG
(Python)
A099004_list, l, s, b1, b2 = [1], 2, 3, set(), set([1])
for n in range(2, 5*10**3+1):
....i = s
....while True:
........m = abs(i-l)
........if not (i in b1 or m in b2):
............A099004_list.append(i-l)
............b1.add(i)
............b2.add(m)
............l = i
............while s in b1:
................b1.remove(s)
................s += 1
............break
........i += 1 # Chai Wah Wu, Dec 15 2014
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 17 2003
EXTENSIONS
Edited by N. J. A. Sloane, Apr 08 2006
More terms from Robert G. Wilson v, Jun 13 2006
STATUS
approved