A125595 a(1)=1, a(n) = the least positive number not yet in sequence which added to max(a(1)..a(n-1)) gives a prime.

1, 2, 3, 4, 7, 6, 10, 9, 13, 16, 15, 21, 8, 20, 22, 19, 25, 12, 18, 28, 31, 30, 36, 5, 11, 17, 23, 35, 37, 24, 34, 42, 29, 41, 47, 14, 26, 32, 50, 33, 39, 51, 38, 46, 52, 27, 45, 49, 55, 48, 54, 58, 43, 69, 40, 44, 62, 68, 70, 57, 61, 67, 79, 60, 72, 78, 84, 53, 65, 73, 83, 89

Offset: 1

Author

Zak Seidov, Nov 26 2006

Keywords

• nonn

Comments

Apparently an arrangement of positive integers. Among the first 1000 terms in the sequence, the first absent numbers are: 809,890,902,908,920,926,932,938,944,945,963,968,977,986,998. Fixed points of the arrangement are: 1,2,3,4,6,61,106,137,419,452,486,557,730.

Examples

			n=7: ss={1,2,3,4,7,6}, max(ss)=7; a(7)=the least positive number d not yet in ss such that max(ss)+d is prime, d=10, 7+10=17, hence a(7)=10.
		

Links

• Zak Seidov, Tableof n, a(n) for n = 1..1000