OFFSET
1,1
EXAMPLE
9.18.19.27.28.37.39.46.48.56 ... <- sequence
.9..1..8..1..9..2..7..2..8 ... <- first differences are the sequence's digits.
MATHEMATICA
a[1] = 9; a[n_] := a[n] = a[n - 1] + Flatten[ Table[ IntegerDigits[ a[i]], {i, n - 1}]][[n - 1]]; Table[ a[n], {n, 56}] (* Robert G. Wilson v, Jun 15 2005 *)
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Eric Angelini, Jun 12 2005
EXTENSIONS
Edited and extended by Robert G. Wilson v, Jun 15 2005
STATUS
approved