The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A084408 Triangle read by rows: if n is prime, row n contains the n smallest primes not already used; if n is composite, row n contains the n smallest composite numbers not already used. A permutation of the positive integers. 4
 1, 2, 3, 5, 7, 11, 4, 6, 8, 9, 13, 17, 19, 23, 29, 10, 12, 14, 15, 16, 18, 31, 37, 41, 43, 47, 53, 59, 20, 21, 22, 24, 25, 26, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39, 40, 42, 44, 45, 46, 48, 49, 50, 51, 52, 54, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 55, 56, 57, 58, 60 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Ivan Neretin, Table of n, a(n) for n = 1..8001 EXAMPLE 1 2 3 5 7 11 4 6 8 9 13 17 19 23 29 10 12 14 15 16 18 ... MATHEMATICA a = {1}; Do[a = Join[a, Take[Select[Complement[Range[Prime[PrimePi@Max@a + n]], a], ! (PrimeQ[#] \[Xor] PrimeQ[n]) &], n]], {n, 2, 12}]; a (* Ivan Neretin, May 23 2018 *) CROSSREFS Cf. A084409, A084410, A084411. Sequence in context: A179335 A330994 A097858 * A257347 A143345 A111679 Adjacent sequences:  A084405 A084406 A084407 * A084409 A084410 A084411 KEYWORD nonn,easy,tabl AUTHOR Amarnath Murthy, Jun 01 2003 EXTENSIONS Edited and extended by David Wasserman, Dec 27 2004 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 9 09:37 EST 2021. Contains 349627 sequences. (Running on oeis4.)