A105391 - OEIS

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A105391

Numbers m such that there are an equal number of numbers <= m that are contained and that are not contained in the concatenation of terms <= m in A048991.

740, 1260, 1262, 5230, 15804, 15814, 15816, 36294, 194876, 213868 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,1`
	COMMENTS	`A105390(a(n)) = a(n)/2.` `There are no other terms <= 600000. The plots in a105390.gif strongly suggest that the sequence is complete. - Klaus Brockhaus, Aug 15 2007`
	LINKS	`Table of n, a(n) for n=1..10.` `Nick Hobson, Python program for this sequence`
	EXAMPLE	`A105390(n) < n/2 for n < a(1)=740;` `A105390(n) > n/2 for n with 740 < n < a(2)=1260;` `A105390(1261)=631, A105390(a(3))=A105390(1262)=631;` `A105390(n) < n/2 for n with 1262 < n < a(4)=5230;` `A105390(n) > n/2 for n with 5230 < n < a(5)=15804;` `A105390(n) < n/2 for n with 15804 < n < a(6)=15814;` `A105390(15815)=7908, A105390(a(7))=A105390(15816)=7909;` `A105390(n) < n/2 for n with 15816 < n < a(8)=36294;` `A105390(n) > n/2 for n with 36294 < n < a(9)=194876; etc.`
	PROG	`(JBASIC)` `s$ = "" : c = 0 : d = 0` `FOR n = 1 TO 40000` `sn$ = str$(n)` `IF instr(s$, sn$) > 0 THEN d = d+1 ELSE c = c+1 : s$ = s$ + sn$` `IF c = d THEN print n ; ", " ;` `NEXT ' Klaus Brockhaus, Aug 15 2007`
	CROSSREFS	`Cf. A048991, A048992, A105390, A131982 (numbers n such that A131981(n) = n/2).` `Sequence in context: A066402 A243778 A256634 * A319043 A044984 A252576` `Adjacent sequences: A105388 A105389 A105390 * A105392 A105393 A105394`
	KEYWORD	`nonn,base,more`
	AUTHOR	`Reinhard Zumkeller, Apr 04 2005`
	STATUS	`approved`

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Last modified May 25 20:58 EDT 2020. Contains 334597 sequences. (Running on oeis4.)