A210701 -id:A210701 - cp's OEIS frontend

A210700 A047160(3n): smallest m >= 0 with both 3n - m and 3n + m prime.

0, 1, 2, 1, 2, 1, 2, 5, 4, 1, 4, 5, 2, 1, 2, 5, 8, 7, 4, 1, 4, 5, 2, 1, 4, 5, 2, 5, 14, 7, 4, 7, 2, 1, 2, 1, 2, 13, 10, 7, 14, 13, 2, 5, 4, 1, 10, 5, 10, 1, 4, 7, 8, 5, 2, 5, 8, 7, 4, 1, 10, 5, 8, 1, 2, 1, 10, 7, 16, 13, 14, 17, 8, 11, 2, 1, 2, 5, 4, 1, 14, 5

Offset: 1

Jason Kimberley, Oct 15 2012

This sequence is interesting because, apart from a(2)=1, A155764 appears to consist only of multiples of three. Equivalently, since n and A047160(n) are coprime (for nonzero A047160(n)), no multiple of three appears to occur in A155765.

Jason Kimberley, Table of n, a(n) for n = 1..3333
OEIS (Plot 2), Plot of (log(n), log(a(n)))
OEIS (Plot 2), Plot of (log(A210701(n)), log(A210702(n)))

Cf. A210701 (location of records in this sequence), A210702 (records in this sequence).

sml[n_]:=Module[{m=0},While[!PrimeQ[3n-m]||!PrimeQ[3n+m],m++];m]; Array[ sml,100] (* Harvey P. Dale, Sep 23 2022 *)

A210702 Records in A210700.

Original entry on oeis.org

0, 1, 2, 5, 8, 14, 16, 17, 19, 20, 25, 35, 38, 55, 62, 67, 73, 82, 121, 130, 140, 160, 191, 232, 233, 245, 260, 283, 308, 379, 391, 437, 481, 607, 650, 673, 784, 790, 841, 856, 920, 1036, 1114, 1234, 1241, 1316, 1402, 1504, 1540, 1610, 1684, 1774, 1811

Offset: 1

Jason Kimberley, Oct 15 2012

nonn

Cf. A210701 (location of records).

sml[n_]:=Module[{m=0},While[!PrimeQ[3n-m]||!PrimeQ[3n+m],m++];m]; DeleteDuplicates[ Array[sml,3000000],GreaterEqual] (* The program generates the first 43 terms of the sequence. *) (* Harvey P. Dale, Sep 23 2022 *)

a(n) = A210700(A210701(n)).

cp's OEIS Frontend

A210700 A047160(3n): smallest m >= 0 with both 3n - m and 3n + m prime.

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