A379455 Numbers that decrease two times in succession when they are iteratively replaced by the "Look and Say" description (cf. A045918) of their prime factors, counted with multiplicity.

1849, 7921, 38809, 79507, 146529, 160801, 200978, 226981, 327697, 654481, 1113032, 1653125, 1731619, 1765376, 2109375, 2588881, 3418927, 3857868, 4182703, 5640625, 6492304, 6553600, 6892100, 7103125, 7845601, 8438707, 9509327, 11039981, 11880448, 12068352, 12106067, 12584111, 13227109, 14895500, 16843208, 17149469, 17372224, 18081075, 18852697, 19523584

Offset

1,1

Links

Scott R. Shannon, Table of n, a(n) for n = 1..568

Example

1849 is a term as 1849 = 43^2 which becomes 243 when replaced by the "Look and Say" description of its prime factors, and 243 is smaller than 1849, and 243 = 3^5 which becomes 53 when replaced by the "Look and Say" description of its prime factors, and 53 is smaller than 243.

Crossrefs

Cf. A045918, A379453, A379454, A005150, A367974, A369132, A369092.

Sequence in context: A326318 A115719 A062670 * A206468 A031764 A031674

Adjacent sequences: A379452 A379453 A379454 * A379457 A379467 A379468

Keyword

nonn,new

Author

Scott R. Shannon, Dec 23 2024

Status

approved