This site is supported by donations to The OEIS Foundation.

 Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A260274 Given a number n with k digits, enumerate the positions of the digits starting from LSD = 1 to MSD = k. Then concatenate in ascending order the positions of the minimum digit in n. Repeat the same process for all the different digits, in ascending order, in n. Sequence lists the fixed points of this transform. 4
 1, 2413, 3142, 25314, 41352, 28463517, 28536417, 34872156, 35827146, 43781265, 46281735, 53718264, 56218734, 64172853, 65127843, 71463582, 71536482 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS If x is in the sequence, then the digit reversal of x also belongs to the sequence. If we consider the numbers that under this transform produce a multiple of the number itself, for n <= 10^8 we should add only 153363. Digit 1 is in position 6, 3 in position 1, 3 and 4, 5 in position 5, 6 in position 2. Finally, 613452 / 153363 = 4. LINKS EXAMPLE In 2413, digit 1 is in position 2, 2 in position 4, 3 in position 1, 4 in position 3. Therefore concat(2,4,1,3) = 2413 that is a fixed point. In 56218734 digit 1 is in position 5, 2 in position 6, 3 in position 2, 4 in position 1, 5 in position 8, 6 in position 7, 7 in position 3, 8 in position 4. Therefore concat(5,6,2,1,8,7,3,4) = 56218734 that is a fixed point. MAPLE with(numtheory):P:=proc(q) local a, b, j, k, n; for n from 1 to q do a:=convert(n, base, 10); b:=0; for k from 0 to 9 do for j from 1 to nops(a) do if a[j]=k then b:=b*10+j; fi; od; od; if b=n then print(n); fi; od; end: P(10^9); CROSSREFS Cf. A260275, A260385, A260386. Sequence in context: A031727 A236038 A283783 * A234126 A159346 A256835 Adjacent sequences:  A260271 A260272 A260273 * A260275 A260276 A260277 KEYWORD nonn,base,fini AUTHOR Paolo P. Lava, Jul 24 2015 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 15 20:10 EST 2018. Contains 318154 sequences. (Running on oeis4.)