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
Keywords
Examples
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.
Links
- Scott R. Shannon, Table of n, a(n) for n = 1..568