A142728 Nonprimes of the form (p(n)-2*n)/3, where p(n)=n-th prime.

0, 1, 1, 35, 35, 39, 45, 45, 49, 75, 77, 81, 95, 105, 115, 119, 143, 145, 147, 159, 187, 187, 207, 217, 219, 235, 235, 243, 249, 267, 273, 289, 321, 325, 335, 339, 361, 365, 369, 369, 381, 381, 395, 395, 411, 411, 417, 427, 441, 459, 465, 471, 471, 485, 485

Offset

1,4

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

If n=1, then (p(1)-2*1)/3=!2-2)/3=0=a(1).
If n=7, then (p(7)-2*7)/3=(17-14)/3=1=a(2).
If n=8, then (p(8)-2*8)/3=(19-16)/3=1=a(3).
If n=38, then (p(38)-2*38)/3=(163-76)/3=29=a(4).
If n=55, then (p(55)-2*55)/3=(257-110)/3=49=a(5).
If n=74, then (p(74)-2*74)/3=(373-148)/3=75=a(6).
If n=76, then (p(76)-2*14)/3=(383-152)/3=77=a(7), etc.

Mathematica

Select[Table[(Prime[n]-2n)/3, {n, 0, 500}], IntegerQ[#]&&!PrimeQ[#]&] (* Harvey P. Dale, Oct 18 2023 *)

Crossrefs

Cf. A000040, A141468.

Sequence in context: A307509 A291654 A257948 * A316111 A316348 A146205

Adjacent sequences: A142725 A142726 A142727 * A142729 A142730 A142731

Keyword

nonn

Author

Juri-Stepan Gerasimov, Oct 07 2008

Extensions

Corrected (29 replaced by double-35, 39 and 45, 115 inserted, 145 inserted, 338 replaced by 339 etc.) - R. J. Mathar, Apr 18 2010

Status

approved