A079669 a(n) = least k such that the distance from Fibonacci(k) to the closest prime is n, or -1 if no such k exists.

3, 1, 0, 9, 16, 12, 37, 42, 149, 33, 26, 27, 38, 24, 28, 189, 44, 111, 50, 66, 49, 57, 68, 30, 46, 81, 142, 78, 92, 96, 59, 69, 71, 141, 184, 267, 67, 129, 61, 117, 211, 576, 115, 372, 161, 138, 119, 198

Offset: 0

Author

Benoit Cloitre, Jan 26 2003

Keywords

• nonn

Crossrefs

Cf. A051699, A000045.

Programs

PARI

a(n)=if(n<0,0,s=1; while(abs(n-min(abs(precprime(fibonacci(s))-fibonacci(s)),abs(nextprime(fibonacci(s))-fibonacci(s))))>0,s++); s)

Extensions

Changed "was found" to "exists" in definition. Offset was wrong. Adjusted initial terms. - N. J. A. Sloane, Jan 29 2022