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A094406 Smallest unhappy number that takes n steps to reach any of the unhappy cycle (4, 16, 37, 58, 89, 145, 42, 20) under iteration of sum of squares of digits map. 2
4, 2, 11, 15, 5, 3, 14, 45, 36, 6, 112, 269, 15999 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,1

COMMENTS

This sequence is an analog of sequence A001273 with the unhappy numbers instead of the happy numbers.

LINKS

Table of n, a(n) for n=4..16.

W. Schneider, Unhappy Numbers.

EXAMPLE

15 is the fourth term because: 15: 1^2 + 5^2 = 26 / 26: 2^2 + 6^2 = 40 / 40: 4^2 + 0^2 = 16 and 16 is a member of the unhappy number series (4, 16, 37, 58, 89, 145, 42, 20)

CROSSREFS

Cf. A001273.

Sequence in context: A213568 A185878 A182870 * A142706 A092952 A286145

Adjacent sequences:  A094403 A094404 A094405 * A094407 A094408 A094409

KEYWORD

nonn,base

AUTHOR

Sergio Pimentel, Apr 30 2004

EXTENSIONS

The next term, 577999999999....999999999999 (199 digits) is too large to include.

Edited by Charles R Greathouse IV, Aug 03 2010

STATUS

approved

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Last modified September 23 21:16 EDT 2017. Contains 292391 sequences.