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

1,2

Links

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

Example

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

Mathematica

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

Crossrefs

Cf. A067112, A067113, A067114.

Sequence in context: A225004 A339857 A074373 * A061077 A292675 A254719

Adjacent sequences: A067112 A067113 A067114 * A067116 A067117 A067118

Keyword

easy,nonn,base

Author

Amarnath Murthy, Jan 08 2002

Status

approved