A143344 First differences of A022941.

1, 3, 4, 6, 7, 8, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 77

Offset: 1

Author

N. J. A. Sloane, Nov 01 2009

Keywords

• nonn
• easy

Comments

This is (essentially) the sequence c() mentioned in the definition of A022941.

Links

• Nathaniel Johnston, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A022941, A156031.

Programs

Haskell

import Data.List (delete)
a143344 n = a143344_list !! (n-1)
a143344_list = zipWith (-) (tail a022941_list) a022941_list
-- Reinhard Zumkeller, May 17 2013

Maple

a[1]:=1: a[2]:=2: c[1]:=3: for n from 2 to 70 do c[n]:=c[n-1]+1: for k from 1 to n do if(c[n]<=a[k])then if(c[n]=a[k])then c[n]:=c[n]+1: fi: break: fi: od: a[n+1]:=a[n]+c[n-1]: od: seq(c[n],n=1..70); # Nathaniel Johnston, May 01 2011

Extensions

a(26), a(27) corrected by Nathaniel Johnston, May 01 2011