A075537 a(1)=1, a(2)=2, then use "merge and minus": a(n)=merge(a(n-2),a(n-1))-a(n-2)-a(n-1).

1, 2, 9, 18, 891, 17982, 89099109, 1798199982018, 890991089999910900891, 1798199982017999999998201800017982, 8909910899999109008909999999999999109008910000089099109

Offset

1,2

Comments

A rapidly growing sequence. An even more rapidly growing sequence with "merge and minus" rule is A075538.

Links

Table of n, a(n) for n=1..11.

Example

a(3)=9 because a(1)=1, a(2)=2 and a(3)=merge(a(1), a(2))-a(1)-a(2)=12-1-2=9; a(4)=18 because a(2)=2, a(3)=9 and a(4)=merge(a(2), a(3))-a(2)-a(3)=29-2-9=18.

Mathematica

se={1, 2}; a=1; b=2; Do[ab=ToExpression[ToString[a]<>ToString[b]]-a-b; se=Append[se, ab]; a=b; b=ab, {i, 10}]; se

Crossrefs

Cf. A075538.

Sequence in context: A006226 A109298 A297470 * A342473 A342619 A342471

Adjacent sequences: A075534 A075535 A075536 * A075538 A075539 A075540

Keyword

nonn

Author

Zak Seidov, Sep 20 2002

Status

approved