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 A138758 Index of A001203(n) (continued fraction for pi) in A000040 (primes), or 0 if A001203(n) is not prime. 3
 2, 4, 0, 0, 0, 0, 0, 0, 1, 0, 2, 0, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 0, 0, 0, 2, 6, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 2, 3, 0, 0, 0, 0, 0, 4, 0, 1, 2, 4, 0, 1, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 3, 1, 1, 2, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 2, 0, 1, 0, 0, 0, 1, 3, 0, 0, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS FORMULA a(n) = A000720(A001203(n)) * A010051(A001203(n)) EXAMPLE This sequence starts 2,4,0,0,... since the first and 2nd terms of the continued fraction expansion of Pi, A001203 = (3, 7, 15, 1,...) are the 2nd resp. 4th primes, while the next two terms are not primes. PROG (PARI) default(realprecision, 1000); t=contfrac(Pi); vector(#t, i, isprime(t[i])*primepi(t[i])) CROSSREFS Cf. A001203, A138757, A138759, A005042. Sequence in context: A166926 A266296 A028573 * A107501 A126732 A028586 Adjacent sequences:  A138755 A138756 A138757 * A138759 A138760 A138761 KEYWORD nonn AUTHOR M. F. Hasler, Mar 31 2008 STATUS approved

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Last modified August 11 15:12 EDT 2020. Contains 336428 sequences. (Running on oeis4.)