A129259 Row 1 of prime separator array A129258.

1, 2, 4, 7, 9, 13, 15, 18, 23, 25, 29, 31, 36, 40, 42, 46, 49, 51, 55, 58, 61, 63, 67, 71, 78, 80, 83, 85, 89, 92, 97, 102, 105, 109, 111, 113, 117, 122, 127, 130, 134, 136, 139, 142, 150, 152, 156, 159, 161, 166, 169, 173, 177, 179, 185, 187, 192, 194, 196, 199

Offset

1,2

Comments

This contains the primes 2,7,13,23,29,31. A129260 contains all primes not here.

Links

Table of n, a(n) for n=1..60.

Formula

A129258 is the sequence T(n,1) defined as follows. T(1,1)=1. For n>=1, let S(n)={(i,j): 1<=i<=n and 1<=j<=n}. Once T(i,j) is defined on S(n), define T(1,n+1)=least positive integer (l.p.i.) not among T(i,j) for (i,j) in S(n); T(n+1,1)=l.p.i. not among T(i,j) for (i,j) in S(n) and not T(1,n+1); T(m,n+1)=T(m,1)*T(1,n+1) for m=2,3,...,n+1; T(n+1,m)=T(n+1,1)*T(1,m) for m=2,3,...,n+1.

Example

Row 1 of the array A129258 with northwest corner
1 2 4 7 9 13 15 18
3 6 12 21 27 39 45 54
5 10 20 35 45 65 75 90
8 16 32 56 72 104 120 144
11 22 44 77 99 143 165 198

Crossrefs

Cf. A129258, A129260.

Sequence in context: A195669 A277733 A288933 * A077597 A183873 A036386

Adjacent sequences: A129256 A129257 A129258 * A129260 A129261 A129262

Keyword

nonn

Author

Clark Kimberling, Apr 06 2007

Status

approved