A278998 Numbers of the form (5h+1)*5^k-1 or (5h+4)*5^k-1 for h,k in N.

0, 3, 4, 5, 8, 10, 13, 15, 18, 19, 20, 23, 24, 25, 28, 29, 30, 33, 35, 38, 40, 43, 44, 45, 48, 50, 53, 54, 55, 58, 60, 63, 65, 68, 69, 70, 73, 75, 78, 79, 80, 83, 85, 88, 90, 93, 94, 95, 98, 99, 100, 103, 104, 105, 108, 110, 113, 115, 118, 119, 120, 123, 124, 125, 128, 129, 130

Offset

1,2

Links

Ray Chandler, Table of n, a(n) for n = 1..10000

Hao Fu, G.-N. Han, Computer assisted proof for Apwenian sequences related to Hankel determinants, arXiv preprint arXiv:1601.04370 [math.NT], 2016. See sequence "J" in Section 2.2.

Mathematica

isok[n_]:=Module[{ord=IntegerExponent[n+1, 5]}, MemberQ[{1, 4}, Mod[(n+1)/5^ord, 5]]]; Select[Range[0, 131], isok] (*Ray Chandler, Dec 17 2016*)

Crossrefs

Complement of A278999.

Sequence in context: A239142 A028288 A118250 * A211533 A079136 A235862

Adjacent sequences: A278995 A278996 A278997 * A278999 A279000 A279001

Keyword

nonn

Author

N. J. A. Sloane, Dec 07 2016

Extensions

More terms from Ray Chandler, Dec 17 2016

Status

approved