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A074923 Number of steps to reach the first integer starting with prime(n+1)/prime(n) and iterating the map x -> x*ceiling(x), or -1 if no integer is ever reached. 0
1, 6, 18, 5, 5, 7, 37, 132, 29, 63, 46, 11, 7, 212, 25, 38, 145, 136, 46, 118, 39, 37, 24, 15, 19, 85, 211, 179, 249, 266, 190, 87, 259, 216, 16, 70, 210, 56, 255, 94, 143, 244, 482, 558, 46, 327, 271, 93, 110, 8, 121, 29, 421, 329, 47, 40, 394, 376, 64, 249, 49, 390, 321 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..63.

EXAMPLE

a(4)=5 since A000040(4+1)/A000040(4)=11/7 -> 22/7 -> 88/7 -> 1144/7 -> 187616/7 -> 718381664.

CROSSREFS

Cf. A073524, A000040.

Sequence in context: A209482 A209341 A077022 * A093061 A264028 A078741

Adjacent sequences:  A074920 A074921 A074922 * A074924 A074925 A074926

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Oct 04 2002

EXTENSIONS

Extended by Max Alekseyev, Jul 28 2009

STATUS

approved

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Last modified November 27 15:11 EST 2020. Contains 338683 sequences. (Running on oeis4.)