A170830 A121153 \ A005836.

949, 1036, 2362, 2812, 2847, 3108, 7086, 8436, 8541, 9324, 21258, 25308, 25623, 27972, 28009, 63774, 63973, 66124, 75924, 76869, 83916, 84027, 84253, 191322, 191919, 198372, 227772, 230607, 235228, 251748, 252081, 252759, 253216, 573966, 575757

Offset

1,1

Comments

If n is in this sequence then so is 3n. - Charlie Neder, Feb 25 2019

Links

Charlie Neder, Table of n, a(n) for n = 1..49

Prog

(PARI) is1(n, R=divrem(3^logint(n, 3), n), S=0)={while(R[1]!=1&&!bittest(S, R[2]), S+=1<<R[2]; R=divrem(R[2]*3, n)); R[1]!=1||R[2]==0}
is2(n)={while(n, if(n%3>1, return(0)); n\=3); 1; }
for(n = 1, 1000000, if(is1(n), if(is2(n), , print(n)))) \\ Charlie Neder, Feb 26 2019, from programs for A121153 and A005836

Crossrefs

Cf. A170853, A005836, and the Cantor set sequence A121153.

Sequence in context: A215950 A192770 A187627 * A020366 A217936 A013532

Adjacent sequences: A170827 A170828 A170829 * A170831 A170832 A170833

Keyword

nonn

Author

N. J. A. Sloane, Feb 22 2010

Extensions

Data corrected by Charlie Neder, Feb 25 2019

Status

approved