OFFSET
0,2
COMMENTS
After the 26th term the sequence goes into a cycle of 46 terms.
"Summarize" uses here method C = A244112: in order of decreasing digit value.
LINKS
FORMULA
a(n+1) = A244112(concat(a(n),a(n-1))). - M. F. Hasler, Feb 25 2018
MAPLE
a:= proc(n) option remember; `if`(n<2, 2*n+1, (p-> parse(cat(seq((c->
`if`(c=0, [][], [c, 9-i][]))(coeff(p, x, 9-i)), i=0..9))))(
add(x^i, i=map(x-> convert(x, base, 10)[], [a(n-1), a(n-2)]))))
end:
seq(a(n), n=0..20); # Alois P. Heinz, Jun 18 2022
MATHEMATICA
a[0] = 1; a[1] = 3; a[n_] := a[n] = FromDigits @ Flatten @ Reverse @ Select[ Transpose @ { DigitCount[a[n-1]] + DigitCount[a[n-2]], Append[ Range[9], 0]}, #[[1]] > 0 &];
Table[a[n], {n, 0, 17}] (* Jean-François Alcover, Dec 30 2017 *)
PROG
(PARI) {a=[1, 3]; for(n=1, 50, a=concat(a, A244112(eval(Str(a[n], a[n+1]))))); a} \\ M. F. Hasler, Feb 25 2018
CROSSREFS
KEYWORD
base,easy,nice,nonn
AUTHOR
STATUS
approved