A067115 Let N = 1357911131517192123252729... = concatenation of odd numbers. Then a(n) = sum of first n digits of N.

1, 4, 9, 16, 25, 26, 27, 28, 31, 32, 37, 38, 45, 46, 55, 57, 58, 60, 63, 65, 70, 72, 79, 81, 90, 93, 94, 97, 100, 103, 108

Offset: 1

Author

Amarnath Murthy, Jan 08 2002

Keywords

• easy
• nonn
• base

Examples

			a(6)= 1+3+5+7+9+1 = 26.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A067112, A067113, A067114.

Programs

Mathematica

Module[{nn=20,codd},codd=Flatten[IntegerDigits/@(2Range[0,nn]+1)];Accumulate[ codd]] (* Harvey P. Dale, Jul 09 2021 *)