A061470 First (leftmost) digit - second digit + third digit - fourth digit .... = 1.

1, 10, 21, 32, 43, 54, 65, 76, 87, 98, 100, 111, 122, 133, 144, 155, 166, 177, 188, 199, 210, 221, 232, 243, 254, 265, 276, 287, 298, 320, 331, 342, 353, 364, 375, 386, 397, 430, 441, 452, 463, 474, 485, 496, 540, 551, 562, 573, 584, 595, 650, 661, 672, 683

Offset: 1

Author

Amarnath Murthy, May 05 2001

Keywords

• nonn
• base
• easy

Examples

			221 is in the sequence since 2-2+1 = 1.
		

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A008593, A060978-A060980, A060982, A061470-A061479, A061870-A061882.

Cf. A225693.

Programs

Haskell

a061470 n = a061470_list !! (n-1)
a061470_list = filter ((== 1) . a225693) [0..]
-- Reinhard Zumkeller, Aug 08 2014

Mathematica

d[n_]:=IntegerDigits[n]; a[n_]:=Differences[Reverse[Total/@{Take[d[n],{1,-1,2}],Take[d[n],{2,-1,2}]}]]; Select[Range[690],a[#]=={1} &] (* Jayanta Basu, May 18 2013 *)
Select[Range[1000],Total[Times@@@Partition[Riffle[IntegerDigits[#],{1,-1},{2,-1,2}],2]]==1&] (* Harvey P. Dale, May 24 2021 *)

Formula

A225693(a(n)) = 1. - Reinhard Zumkeller, Aug 08 2014

Extensions

More terms from Robert G. Wilson v, May 10 2001 and from Larry Reeves (larryr(AT)acm.org), May 14 2001