A107892 Index of first occurrence of n-th prime in A001203, the continued fraction for Pi.

9, 1, 40, 2, 276, 28, 647, 140, 203, 243, 878, 784, 754, 492, 825, 1547, 907, 868, 1789, 9215, 898, 6222, 9131, 4829, 1516, 6700, 22640, 872, 11170, 3204, 223, 10387, 8299, 30086, 31079, 12637, 8486, 20644, 8451, 53069, 32093, 16297, 20276, 1002, 21264

Offset: 1

Author

Zak Seidov, May 25 2005

Keywords

• nonn

Comments

Until it is proved that every prime does indeed occur in A001203, we should tacitly understand a convention like "A107892(n) = 0 if A000040(n) does not occur in A001203". - M. F. Hasler, Mar 31 2008

Among first 1000000 terms of the continued fraction for Pi, the first absent primes have indices 129, 132, 137, 146, 147, 158, 160, 165, 170, 172, 175, 180, 182, 184, 189, 193, 197, 198, 199. The 200th prime is in the 947040th place, thus A107892(200)=947040.

Links

• M. F. Hasler (using data from H. Havermann), Table of n, a(n) for n=1,...,445.

Crossrefs

Cf. A032523: first occurrence of n in A001203.

Cf. A138758, A138759.

Formula

A107892(n) = A032523(A000040(n)) = min { k | A001203(k)=A000040(n) }. - M. F. Hasler, Mar 31 2008

Extensions

Edited by M. F. Hasler, Mar 31 2008