|
| |
|
|
A079066
|
|
"Memory" of prime(n): the number of (previous) primes contained as substrings in prime(n).
|
|
17
| |
|
|
0, 0, 0, 0, 0, 1, 1, 0, 2, 1, 1, 2, 0, 1, 1, 2, 1, 0, 1, 1, 2, 1, 1, 0, 1, 0, 1, 1, 0, 3, 2, 3, 4, 2, 0, 1, 2, 1, 2, 4, 3, 0, 1, 2, 3, 1, 2, 3, 2, 2, 3, 3, 2, 2, 3, 2, 1, 3, 2, 1, 3, 3, 2, 3, 3, 4, 2, 3, 3, 1, 3, 3, 3, 4, 4, 2, 2, 3, 0, 0, 2, 1, 3, 2, 2, 2, 0, 2, 1, 1, 2, 3, 1, 0, 0, 2, 1, 2, 4, 2, 3, 2, 2, 1, 3
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,9
|
|
|
LINKS
| Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
|
|
|
FORMULA
| A039997(prime(n)) - 1.
|
|
|
EXAMPLE
| The primes contained as substrings in prime(3) = 113 are 3, 11, 13. Hence a(30) = 3. 113 is the smallest prime with memory = 3.
|
|
|
MATHEMATICA
| ub = 105; tprime = Table[ToString[Prime[i]], {i, 1, ub}]; a = {}; For[i = 1, i <= ub, i++, m = 0; For[j = 1, j < i, j++, If[Length[StringPosition[tprime[[i]], tprime[[j]]]] > 0, m = m + 1]]; a = Append[a, m]]; a
|
|
|
PROG
| (Haskell)
import Data.List (isInfixOf)
a079066 n =
length $ filter (`isInfixOf` (primesDec !! n)) $ take n primesDec
primesDec = "_" : map show a000040_list
-- Reinhard Zumkeller, Jul 19 2011
|
|
|
CROSSREFS
| Cf. A079075, A035232.
Cf. A033274, A179909, A179910, A179911, A179912, A179913, A179914, A179915, A179916, A179917, A179918, A179919, A179922.
Sequence in context: A137412 A025925 A109066 * A157188 A173266 A096496
Adjacent sequences: A079063 A079064 A079065 * A079067 A079068 A079069
|
|
|
KEYWORD
| base,easy,nonn
|
|
|
AUTHOR
| Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Feb 02 2003
|
|
|
EXTENSIONS
| Edited by Robert G. Wilson v (rgwv(AT)rgwv.com), Feb 25 2003
|
| |
|
|
