This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A228092 Lexicographically first sequence of nonprime terms (with no duplicates) that turns into a sequence of prime terms (with no duplicates) by applying the "comma-permutation" simultaneously at every comma. [The "comma-permutation" is explained in the Comments section.] 2
 1, 21, 12, 32, 33, 91, 14, 72, 111, 15, 92, 321, 301, 102, 322, 721, 901, 702, 931, 312, 332, 942, 152, 153, 74, 75, 34, 93, 703, 711, 121, 731, 132, 762, 361, 932, 972, 171, 741, 951, 154, 704, 104, 912, 981, 161, 362, 781, 371, 372, 992, 3002, 3012, 1011, 782, 1022, 7021, 993, 112, 3031, 994, 323 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The "comma-permutation" swaps the last digit of a(n) and the first digit of a(n+1) for every n. For instance [2016,2017] becomes [2012,6017] and [2016,2017,2018] turns into [2012,6012,7018]. The sequence is always extended with the smallest integer not yet present that does not lead to a contradiction. No term ends in "0" as this "0" would start a term of the prime sequence. Needs a bigger b-file. - NJAS LINKS Eric Angelini, Table of n, a(n) for n = 1..205 EXAMPLE Under the "comma-permutation" the nine nonprime terms [1,21,12,32,33,91,14,72,111,15] become the primes [2,11,13,23,29,31,17,41,211]. CROSSREFS Cf. A274408. Sequence in context: A260527 A260529 A166033 * A071262 A083466 A307312 Adjacent sequences:  A228089 A228090 A228091 * A228093 A228094 A228095 KEYWORD nonn,base AUTHOR Eric Angelini and Jean-Marc Falcoz, Jun 17 2016 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 10 12:30 EST 2019. Contains 329895 sequences. (Running on oeis4.)