A051729 Smallest number at distance 2n+1 from nearest prime.

1, 26, 118, 120, 532, 1140, 1340, 1342, 1344, 15702, 15704, 19632, 19634, 31424, 31426, 31428, 31430, 31432, 155958, 155960, 155962, 155964, 360698, 360700, 370310, 370312, 370314, 370316, 492170, 1349592, 1357262, 1357264, 1357266, 2010800, 2010802, 2010804, 2010806

Offset

0,2

Links

Table of n, a(n) for n=0..36.

Formula

a(n) = A051652(2*n+1). - Sean A. Irvine, Oct 01 2021

Mathematica

seq[max_] := Module[{s = Table[0, {max}], c = 1, n = 4}, s[[1]] = 1; While[c < max, i = (Min[n - NextPrime[n, -1], NextPrime[n] - n] + 1)/2; If[i <= max && s[[i]] == 0, c++; s[[i]] = n]; n += 2]; s] ; seq[20] (* Amiram Eldar, Aug 28 2021 *)
With[{tbl=Table[{n, If[PrimeQ[n], 2, Min[n-NextPrime[n, -1], NextPrime[n]-n]]}, {n, 500000}]}, Table[SelectFirst[tbl, #[[2]]==2k+1&], {k, 0, 28}]][[;; , 1]] (* The program generates the first 29 terms of the sequence. *) (* Harvey P. Dale, Jul 06 2025 *)

Crossrefs

Related sequences: A023186-A023188, A046929-A046931, A051650, A051652, A051697-A051702, A051728-A051730.

Sequence in context: A221570 A100161 A100162 * A100163 A296325 A183066

Adjacent sequences: A051726 A051727 A051728 * A051730 A051731 A051732

Keyword

nonn,easy,nice

Author

N. J. A. Sloane

Extensions

More terms from James Sellers, Dec 07 1999

More terms from Amiram Eldar, Aug 28 2021

Status

approved