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 A152423 A version of the Jacobus problem. Counting people out of a circle. Who will be the survivor? 1
 1, 2, 2, 4, 2, 4, 6, 8, 2, 4, 6, 8, 10, 12, 14, 16, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) is last person who remains in the circle which starts with n people. Method of counting: start at 0 and next person counts 1 and next is 0,1,0,1 and so on. While who count as 0 need to out of the circle Every people has a number and start counting at person 1 then 2,3,4. Apparently a(n) = 2*A062050(n-1), n>1. - Paul Curtz, May 30 2011 LINKS FORMULA a(1)=1 a(2)=2 if n < a(n-1)+2 => a(n)=2 else => a(n)=a(n-1)+2. EXAMPLE From Omar E. Pol, Dec 16 2013: (Start) It appears that this is also an irregular triangle with row lengths A011782 as shown below: 1; 2; 2,4; 2,4,6,8; 2,4,6,8,10,12,14,16; 2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32; 2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40, 42,44,46,48,50,52,54,56,58,60,62,64; Right border gives A000079. (End) PROG (Other) function F(\$in){ \$a[1] = 1; if(\$in == 1){ return \$a; } \$temp =2; for(\$i=2; \$i<=\$in; \$i++){ \$temp+=2; if(\$temp>\$i){ \$temp = 2 ; } \$answer[] = \$temp; } return \$answer; } #change \$n value for the result \$n=5; #sequence store in \$answer by useing \$a = F(\$n); #to display a(n) echo \$a[n]; CROSSREFS The Index to the OEIS lists 19 entries under "Jacobus problem". - N. J. A. Sloane, Dec 04 2008 Sequence in context: A063789 A106264 A278535 * A233765 A233781 A233971 Adjacent sequences:  A152420 A152421 A152422 * A152424 A152425 A152426 KEYWORD easy,nonn AUTHOR Suttapong Wara-asawapati (retsam_krad(AT)hotmail.com), Dec 03 2008 STATUS approved

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Last modified October 15 10:15 EDT 2019. Contains 328026 sequences. (Running on oeis4.)