A173823 a(n) shows the digit sum of a(n+1) + a(n+2).

1, 2, 8, 3, 5, 7, 16, 9, 6, 12, 21, 18, 82, 17, 27, 25, 36, 14, 10, 30, 34, 68, 35, 45, 57, 46, 4, 11, 20, 54, 47, 56, 50, 55, 49, 64, 26, 77, 24, 19, 84, 33, 29, 73, 28, 15, 38, 31, 13, 87, 52, 63, 41, 61, 39, 66, 42, 72, 40, 70, 51, 91, 22, 23, 78, 32, 48, 53, 59, 43, 65, 37, 67, 44, 62

Offset

1,2

Comments

a(1) = 1, a(2) = 2, and for n > 2 a(n) is the smallest integer not yet present in the sequence such that the digital sum of a(n) + a(n-1) is a substring of the decimal digits of a(n-2).

Links

Charles R Greathouse IV, Table of n, a(n) for n=1..10000

Eric Angelini, Visible DigitSums (sequence U)

E. Angelini, Visible DigitSums [Cached copy, with permission]

Example

a(1) = 1, so A007953(a(2) + a(3)) must have a "1" amongst its digits; the first non-repeat is 10, so a(3) = 8 so a(2) + a(3) = 10.

Crossrefs

Cf. A173821, A173822.

Sequence in context: A201748 A011431 A243340 * A278115 A222296 A258223

Adjacent sequences: A173820 A173821 A173822 * A173824 A173825 A173826

Keyword

base,nonn,look

Author

Charles R Greathouse IV and Eric Angelini, Mar 01 2010

Status

approved