login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A001129 Iccanobif numbers: reverse digits of two previous terms and add. 35
0, 1, 1, 2, 3, 5, 8, 13, 39, 124, 514, 836, 1053, 4139, 12815, 61135, 104937, 792517, 1454698, 9679838, 17354310, 9735140, 1760750, 986050, 621360, 113815, 581437, 1252496, 7676706, 13019288, 94367798, 178067380 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

T. D. Noe and Alois P. Heinz, Table of n, a(n) for n = 0..1000 (first 301 terms from T. D. Noe)

MAPLE

R:= n-> (s-> parse(cat(s[-i]$i=1..length(s))))(""||n):

a:= proc(n) option remember; `if`(n<2, n,

       R(a(n-1)) +R(a(n-2)))

    end:

seq(a(n), n=0..50);  # Alois P. Heinz, Jun 18 2014

MATHEMATICA

Clear[ BIF ]; BIF[ 0 ]=0; BIF[ 1 ]=1; BIF[ n_Integer ] := BIF[ n ]=Plus@@Map[ Plus@@(#*Array[ 10^#&, Length[ # ], 0 ])&, Map[ IntegerDigits, {BIF[ n-1 ], BIF[ n-2 ]} ] ]; Array[ BIF, 40, 0 ]

nxt[{a_, b_}]:={b, Total[FromDigits/@Reverse/@IntegerDigits[ {a, b}]]}; Transpose[NestList[nxt, {0, 1}, 40]][[1]] (* Harvey P. Dale, Jun 22 2011 *)

PROG

(PARI) A001129(n, a=0, b=1)={ n || return; while( n-->0, b=A004086(a)+A004086(a=b)); b }

(Haskell)

a001129 n = a001129_list !! n

a001129_list = 0 : 1 : zipWith (+) iccanobifs (tail iccanobifs)

where iccanobifs = map a004086 a001129_list

-- Reinhard Zumkeller, Jan 01 2012

(Python)

A001129_list, r1, r2 = [0, 1], 1, 0

for _ in range(10**2):

....l, r2 = r1+r2, r1

....r1 = int(str(l)[::-1])

....A001129_list.append(l) # Chai Wah Wu, Jan 03 2015

CROSSREFS

Cf. A001129, A014258-A014260.

See A000045 for the Fibonacci numbers.

Sequence in context: A042163 A273045 A014259 * A281599 A041957 A294939

Adjacent sequences:  A001126 A001127 A001128 * A001130 A001131 A001132

KEYWORD

nonn,base,easy,nice

AUTHOR

N. J. A. Sloane.

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 24 18:03 EDT 2019. Contains 322430 sequences. (Running on oeis4.)