A238593 Smallest m such that the n-th prime occurs as substring in A019518(n).

1, 2, 3, 4, 5, 6, 7, 8, 2, 10, 7, 12, 13, 14, 15, 16, 17, 18, 19, 5, 21, 22, 23, 24, 25, 26, 27, 28, 29, 6, 31, 7, 12, 34, 35, 36, 37, 38, 19, 21, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 32, 59, 60, 61, 11, 63, 33, 12, 7, 66, 68

Offset: 1

Author

Reinhard Zumkeller, Mar 03 2014

Keywords

• nonn
• base

Comments

a(n) <= n; see A165450 for earley bird primes: A165450(n) = A000040(m) with a(m) < m.

Examples

			n=10, prime(10)=29 occurs first in A019518(10)=2357111317192329, therefore a(10) = 10;
prime(11)=31 occurs already in A019518(7)=2357111317, therefore a(11) = 7.
		

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..3333

Programs

Haskell

import Data.List (isInfixOf, findIndex); import Data.Maybe (fromJust)
a238593 n = (+ 1) $ fromJust $ findIndex
   (isInfixOf $ show $ a000040 n) (scanl1 (++) $ map show a000040_list)