A074860 a(n) = a(n-1) + R(a(n-2)) + R(a(n-3)) where a(0)=a(1)=a(2)=1 and R(k) = A004086(k) is the reverse of k.

1, 1, 1, 3, 5, 9, 17, 31, 111, 195, 319, 1021, 2525, 4639, 11092, 25708, 64083, 173846, 292644, 979061, 2073724, 2680995, 7115676, 17380240, 30136219, 41109707, 136581181, 298634398, 550610143, 1625232666, 2859685613, 9863026929, 19691221772, 32153295043

Offset

0,4

Links

Table of n, a(n) for n=0..33.

Maple

R:= n-> (s-> parse(cat(s[-i]$i=1..length(s))))(""||n):
a:= proc(n) option remember; `if`(n<3, 1,
      a(n-1) + R(a(n-2)) + R(a(n-3)))
    end:
seq(a(n), n=0..33);  # Alois P. Heinz, Jun 17 2021

Crossrefs

Cf. A000213, A004086.

Sequence in context: A371911 A000213 A074858 * A374518 A297300 A364543

Adjacent sequences: A074857 A074858 A074859 * A074861 A074862 A074863

Keyword

easy,base,nonn

Author

Felice Russo, Sep 11 2002

Extensions

Corrected and extended by David Garber, Oct 23 2002

Offset corrected by and more terms from Alois P. Heinz, Jun 17 2021

Status

approved