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A075522 Number of steps to reach the first nonprime (=A075523(n)) starting with the n-th prime p and iterating the map k -> 4*k+(p mod 4), or -1 if no integer is ever reached. 2
1, 1, 1, 3, 3, 2, 1, 2, 1, 1, 2, 2, 1, 1, 2, 1, 2, 1, 3, 1, 2, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 4, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 3, 1, 1, 1, 1, 1, 3, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

a(A075521(n)) > 1;

a(n) = a(A075520(n))+1 for n with A075520(n) prime.

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

A000040(4)=7 and (7 mod 4) = 3: 7 -> 4*7+3=31 -> 4*31+3=127 -> 4*127+3=511 = A075523(4), therefore a(4)=3.

CROSSREFS

Cf. A075520, A075519.

Sequence in context: A060574 A283987 A286443 * A186144 A090544 A283755

Adjacent sequences:  A075519 A075520 A075521 * A075523 A075524 A075525

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Sep 19 2002

STATUS

approved

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Last modified February 23 18:54 EST 2019. Contains 320438 sequences. (Running on oeis4.)