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A278998 Numbers of the form (5h+1)*5^k-1 or (5h+4)*5^k-1 for h,k in N. 2
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified June 14 15:46 EDT 2021. Contains 345026 sequences. (Running on oeis4.)