A385110 Terms of A198587 congruent {1, 3, 7} (mod 8).

17, 35, 75, 151, 1137, 2275, 2417, 4835, 4849, 9699, 19417, 38833, 38835, 72817, 77667, 145635, 154737, 309475, 310385, 620771, 621377, 1242737, 1242755, 2485361, 2485475, 4660337, 4970723, 4971025, 9320675, 9903217, 9942051, 19806435, 19864689, 19884107, 39729379

Offset: 1

Author

Ralf Stephan, Jun 18 2025

Keywords

• nonn

Comments

Sorted set of all A385109(A198587(i)), i>0.

Crossrefs

Cf. A198587, A385109.

Programs

PARI

N=3;for(n=1, 1000000, s=n; t=0; while(s!=1, if(s%2==0, s=s/2, s=(3*s+1)/2; t++); if(s==1&&t==N&&(n%8==1||n%8==3||n%8==7), print1(n,", ") ); ))

Extensions

a(22)-a(31) from Michel Marcus, Jun 19 2025

a(32)-a(35) added using A198587 by Jinyuan Wang, Jun 26 2025