A055629 Beginning of first run of at least n consecutive happy numbers.

1, 31, 1880, 7839, 44488, 7899999999999959999999996, 7899999999999959999999996

Offset

1,2

Comments

This sequence is infinite - see Theorem 3.1 of El-Sedy & Siksek.

Links

Table of n, a(n) for n=1..7.

H. G. Grundman, E. A. Teeple, Sequences of consecutive happy numbers, Rocky Mountain J. Math. 37 (6) (2007) 1905-1916.

Hao Pan, On consecutive happy numbers, J. Numb. Theory 128 (6) (2008) 1646-1654.

Esam El-Sedy and Samir Siksek, On happy numbers, Rocky Mountain J. Math. 30 (2000), 565-570.

R. Styer, Smallest Examples of Strings of Consecutive Happy Numbers, J. Int. Seq. 13 (2010), 10.6.3.

Example

Lambert Klasen (lambert.klasen(AT)postmaster.co.uk), Oct 17 2004: with notation {9:repeat_count_of_digit_nine}, a(8) = 58{9:11}6{9:143}95, a(9) = 16{9:179}4{9:87}95, a(10) = 16{9:181}5{9:696}95.

Crossrefs

Cf. A007770.

Sequence in context: A049081 A069432 A338533 * A131751 A042863 A042860

Adjacent sequences: A055626 A055627 A055628 * A055630 A055631 A055632

Keyword

base,nonn

Author

David W. Wilson, Jun 05 2000

Extensions

The next term a(8) is too large to include.

Entry corrected by Sergio Pimentel, Dec 10 2005

Status

approved