A097470 Number of 0's in the decimal expansion of the lesser of twin primes.

0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 1

Offset

2,104

Comments

n=5000,d=0 in PARI code below.

Links

Table of n, a(n) for n=2..106.

Example

101 is the 9th lesser twin prime so 1 is the 9th entry.

Prog

(PARI) g(n, d) = forprime(x=2, n, if(isprime(x+2), print1(countchr(x, d)", "))) \Count the occurrences of char in string str countchr(str, char) = { local(ln, x, c); str=Str(str); \This allows leaving quotes off input char=Str(char); c=0; ln=length(str); for(x=1, ln, if(mid(str, x, 1)==char, c++); ); return(c) } \ Get a substring of length n from string str starting at position s in str. mid(str, s, n) = { local(v, ln, x, tmp); v =""; tmp = Vec(str); ln=length(tmp); for(x=s, s+n-1, v=concat(v, tmp[x]); ); return(v) }

Crossrefs

Sequence in context: A104157 A073520 A152137 * A230093 A066288 A033322

Adjacent sequences: A097467 A097468 A097469 * A097471 A097472 A097473

Keyword

base,nonn

Author

Cino Hilliard, Aug 24 2004

Status

approved