A090652 Numbers all of whose prime factors end in 7.

7, 17, 37, 47, 49, 67, 97, 107, 119, 127, 137, 157, 167, 197, 227, 257, 259, 277, 289, 307, 317, 329, 337, 343, 347, 367, 397, 457, 467, 469, 487, 547, 557, 577, 587, 607, 617, 629, 647, 677, 679, 727, 749, 757, 787, 797, 799, 827, 833, 857, 877, 887, 889

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..10000

Mathematica

Select[Range[1000], Union[Mod[Transpose[FactorInteger[#]][[1]], 10]]=={7}&] (* Harvey P. Dale, May 28 2014 *)

Prog

(PARI) numbers whose factors end in m endfactm(n, m) = { flag=0; for(x=2, n, y=factor(x); z=y[, 1]; ln=length(z); for(j=1, ln, if(z[j]%10<>m, flag=0; break, flag=1) ); if(flag==1, print1(x", ")) ) }

Crossrefs

Sequence in context: A212117 A160635 A339527 * A062675 A257668 A106095

Adjacent sequences: A090649 A090650 A090651 * A090653 A090654 A090655

Keyword

easy,nonn,base

Author

Cino Hilliard, Dec 13 2003

Status

approved