A085608 Index of the smallest prime starting with n.

5, 1, 2, 13, 3, 18, 4, 23, 25, 26, 5, 31, 6, 35, 36, 38, 7, 42, 8, 304, 47, 48, 9, 53, 54, 56, 58, 60, 10, 63, 11, 453, 67, 69, 71, 73, 12, 76, 78, 79, 13, 82, 14, 86, 88, 89, 15, 93, 94, 96, 682, 98, 16, 100, 102, 103, 105, 107, 17, 110, 18, 807

Offset

1,1

Links

Table of n, a(n) for n=1..62.

Formula

a(n) = PrimePi(A018800(n)). - Michel Marcus, Oct 19 2013

Example

a(4)=13 because prime[13]=41 is the smallest prime starting with 4.

Crossrefs

Cf. A000720, A018800.

Sequence in context: A328199 A289690 A088781 * A258339 A197080 A317823

Adjacent sequences: A085605 A085606 A085607 * A085609 A085610 A085611

Keyword

easy,base,nonn

Author

Zak Seidov, Jul 07 2003

Status

approved