A153005 Primes in toothpick sequence A153003.

7, 31, 127, 211, 487, 571, 643, 811, 1033, 1249, 1663, 1999, 2131, 2179, 2281, 2347, 2467, 3391, 4801, 5059, 6361, 7759, 8191, 8209, 8713, 8779, 8929, 9187, 9343, 9679, 9931, 10687, 13903, 14947, 19009, 19267, 19423, 25057, 26731, 28879, 33289, 35521

Offset

1,1

Links

Table of n, a(n) for n=1..42.

David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-1) for n >= 2.]

N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS

Maple

read("transforms3") ; a139250 := BFILETOLIST("b139250.txt") ; A139250 := proc(n) global a139250; op(n+1, a139250) ; end: A153003 := proc(n) if n =0 then 0; else 1+3/4*(A139250(n+1)-3) ; fi; end: for n from 0 to 400 do p := A153003(n) ; if isprime(p) then printf("%d, ", p) ; fi; od: # R. J. Mathar, Jul 13 2009

Mathematica

a139250 = Cases[Import["https://oeis.org/A139250/b139250.txt", "Table"], {_, _}][[All, 2]];
A139250[n_] := a139250[[n + 1]];
A153003[n_] := If[n == 0, 0, 1 + 3/4*(A139250[n + 1] - 3)];
Reap[Do[p = A153003[n]; If[PrimeQ[p], Sow[p]], {n, 0, 400}]][[2, 1]] (* Jean-François Alcover, Apr 05 2020 *)

Crossrefs

Cf. A139250, A139253, A152998, A152999, A153000, A153002, A153003, A153006, A153009.

Sequence in context: A002588 A327497 A036280 * A056909 A002147 A169785

Adjacent sequences: A153002 A153003 A153004 * A153006 A153007 A153008

Keyword

nonn

Author

Omar E. Pol, Jan 02 2009

Extensions

More terms from R. J. Mathar, Jul 13 2009

Status

approved