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 A247747 Whole number sieve of Pi. 5
 1, 5, 9, 8, 4, 7, 9, 9, 5, 2, 16, 20, 62, 8, 3, 9, 28, 9, 44, 95, 58, 3, 2, 5, 8, 8, 7, 28, 0, 10, 59, 9, 7, 4, 78, 6, 6, 60, 6, 54, 66, 9, 0, 60, 9, 2, 7, 0, 1, 88, 0, 96, 9, 0, 6, 6, 0, 0, 305, 6, 4, 9, 9, 94, 270, 7, 9, 2, 6, 93, 1, 3, 5, 7, 6, 9, 35, 57, 9, 8, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Manfred Scheucher, Table of n, a(n) for n = 1..552 Manfred Scheucher, Sage Script EXAMPLE Find the first occurrence of 0 (the first whole number) in the digits of Pi (only 35 digits in this illustration): 31415926535897932384626433832795028..., and replace it with a space: 31415926535897932384626433832795 28...  Repeat the process with the next whole number, 1: 3 415926535897932384626433832795 28...  Then 2: 3 4159 6535897932384626433832795 28...  Then 3:   4159 6535897932384626433832795 28...  Then 4,5,6,7, etc., until the first occurrence of every counting number is eliminated from the digits of Pi.    1    5   9     8    4           ...  Then consolidate gaps between the remaining digits into a single comma: 1,5,9,8,4,7,9,9,5,2,16,20,6,8,3,9, ...  to produce the first terms in the whole number sieve of Pi. PROG (Python) def arccot(x, unity):     sum = xpower = unity // x     n = 3     sign = -1     while 1:         xpower = xpower // (x*x)         term = xpower // n         if not term:             break         sum += sign * term         sign = -sign         n += 2     return sum def pi(digits):     unity = 10**(digits + 10)     pi = 4 * (4*arccot(5, unity) - arccot(239, unity))     return pi // 10**10 def primes(n):     """ Returns  a list of primes < n """     sieve = [True] * n     for i in xrange(3, int(n**0.5)+1, 2):         if sieve[i]:             sieve[i*i::2*i]=[False]*((n-i*i-1)/(2*i)+1)     return [2] + [i for i in xrange(3, n, 2) if sieve[i]] a = pi(400) b = range(100000) y = str(a) for x in b:     if str(x) in y:         y = y.replace(str(x), " ", 1)#replace first occurrence only while "  " in y:     y = y.replace("  ", " ")#replace long chains of spaces with a single space z = y.split(" ")#split terms into a list z = filter(None, z)#remove null terms f = map(int, z)#convert to integers print(f[0:-1]) # Code for A245770 by David Consiglio, Jr., Jan 03 2015 # Modified by Manfred Scheucher,  Jun 05 2015 CROSSREFS Cf. A000796, A245770, A258640, A258481, A257835. Sequence in context: A255247 A153610 A249385 * A308577 A217249 A091812 Adjacent sequences:  A247744 A247745 A247746 * A247748 A247749 A247750 KEYWORD nonn,base AUTHOR Gil Broussard, Sep 23 2014 EXTENSIONS Corrected and extended by Manfred Scheucher, Jun 05 2015 STATUS approved

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Last modified October 16 21:10 EDT 2019. Contains 328103 sequences. (Running on oeis4.)