A108722 a(1)=11, If a(n-1)=abcde..., where a,b,c,d,e... are the digits, then a(n)=abcde...+a*bcde...+ab*cde...+abc*de...+abcd*e...+....

11, 12, 14, 18, 26, 38, 62, 74, 102, 124, 196, 406, 670, 1090, 2080, 3840, 7880, 20280, 42600, 78200, 151200, 250600, 516800, 1360400, 3104400, 6159600, 20352200, 47244600, 158847200, 705347800, 2813903600, 11272396200, 50903322400

Offset

1,1

Comments

The idea is from Peter Boros, borospet(AT)freemail.hu

Links

Table of n, a(n) for n=1..33.

Example

a(10)=124, a(11)=124+1*24+12*4=124+24+48=196

Maple

a[1]:=11:for n from 2 to 40 do d:=a[n-1]:i:=1:while d>0 do c:=d mod 10: b[i]:=c:i:=i+1:d:=(d-c)/10 od:a[n]:=a[n-1]:for j from 1 to i-2 do f:=sum(b[k]*10^(k-1), k=1..j):g:=sum(b[k]*10^(k-j-1), k=j+1..i-1): a[n]:=a[n]+f*g od: od: seq(a[n], n=1..40);

Crossrefs

Sequence in context: A234021 A264023 A177902 * A246139 A034907 A045987

Adjacent sequences: A108719 A108720 A108721 * A108723 A108724 A108725

Keyword

nonn,base

Author

Miklos Kristof, Jun 21 2005

Status

approved