A082931 a(1) = 1; a(n) = least k > a(n-1) such that a(i)+k is prime for some i < n and each prime of form a(i)+a(j) occurs for unique i <= j.

1, 2, 3, 5, 8, 14, 20, 23, 24, 37, 43, 48, 49, 55, 61, 75, 90, 109, 117, 118, 121, 139, 141, 157, 183, 193, 199, 212, 223, 229, 241, 245, 271, 277, 296, 301, 313, 320, 321, 331, 363, 368, 393, 403, 410, 422, 439, 457, 468, 469, 481, 491, 511, 525, 530, 535, 607

Offset

1,2

Links

Table of n, a(n) for n=1..57.

Mathematica

a[1]=1; p[1]={2}; a[n_] := Module[{k, new}, For[k=a[n-1]+1, Intersection[p[n-1], (new=Select[(a/@Range[n-1])+k, PrimeQ])]!={}||new=={}, k++, Null]; p[n]=Union[p[n-1], new]; a[n]=k]

Crossrefs

Cf. A082932, A082933, A080435.

Sequence in context: A117566 A123000 A132599 * A034413 A034416 A306912

Adjacent sequences: A082928 A082929 A082930 * A082932 A082933 A082934

Keyword

nonn

Author

David W. Wilson, Apr 14 2003

Status

approved