# [seqfan] Problem with A086224 cross refs

Jeremy Gardiner jeremy.gardiner at btinternet.com
Fri Oct 21 21:03:15 CEST 2011

```A086224    a(0) = 6, a(n+1) = 2*a(n) + 1 (or a(n)=-1+7*2^n)
6,13,27,55,111,223,447,895,1791,3583, ...

CROSSREFS
a(0) = 2 gives A055010 except for initial terms  - OK (better A153893)
a(0) = 4 gives A052549 except initial terms      - OK (better A153894)
a(0) = 6 gives A086224                           - OK
a(0) = 8 gives A052549 except initial terms      - Actually A052996
a(0) = 10 gives A086225                          - OK
a(0) = 12 gives A086226                          - Not in the OEIS
a(0) = 14 gives A086227                          - Actually A196305
a(0) = 16 gives A086228                          - Not in the OEIS
a(0) = 18 gives A086229                          - Not in the OEIS

Also a(0) = 20 gives A171389

It appears some sequences may have been deleted/rejected and the A-numbers
re-used: I can correct the cross refs - but how about adding the missing
sequences?

Jeremy Gardiner

```