This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
a004086 = read . reverse . show -- Reinhard Zumkeller, Apr 11 2011
|.&.": i.@- 1e5 NB. Stephen Makdisi, May 14 2018
read transforms; A004086 := digrev; #cf "Transforms" link at bottom of page A004086:=proc(n) local s,t; if n<10 then n else s:=irem(n,10,'t'); while t>9 do s:=s*10+irem(t,10,'t') od: s*10+t fi end; # M. F. Hasler, Jan 29 2012
Table[FromDigits[Reverse[IntegerDigits[n]]], {n, 0, 75}]
IntegerReverse[Range[0,80]](* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 13 2018 *)
dig(n) = {local(m=n,r=[]); while(m>0,r=concat(m%10,r);m=floor(m/10));r}
A004086(n) = {local(b,m,r);r=0;b=1;m=dig(n);for(i=1,matsize(m)[2],r=r+b*m[i];b=b*10);r} \\ Michael B. Porter, Oct 16 2009
A004086(n)=fromdigits(Vecrev(digits(n))) \\ M. F. Hasler, Nov 11 2010, updated May 11 2015, Sep 13 2019
def A004086(n): return int(str(n)[::-1]) # Chai Wah Wu, Aug 30 2014
a(17) = 25 because 17 in base 3 is 122, and backwards that is 221, which is 25 in base 10. a(18) = 2 because 18 in base 3 is 200, and backwards that is 2.
a030102 = foldl (\v d -> 3 * v + d) 0 . a030341_row -- Reinhard Zumkeller, Dec 16 2013
a030102:= proc(n) option remember; local y; y:= n mod 3; 3^ilog[3](n)*y + procname((n-y)/3) end proc: for i from 0 to 2 do a030102(i):= i od: seq(a030102(i),i=0..100); # Robert Israel, Dec 24 2015 # alternative A030102 := proc(n) local r ; r := ListTools[Reverse](convert(n,base,3)) ; add(op(i,r)*3^(i-1),i=1..nops(r)) ; end proc: # R. J. Mathar, May 28 2016
A030102[n_] := FromDigits[Reverse@IntegerDigits[n, 3], 3] (* JungHwan Min, Dec 23 2015 *) FromDigits[#,3]&/@(Reverse/@IntegerDigits[Range[0,80],3]) (* Harvey P. Dale, Feb 05 2020 *)
a(n,b=3)=subst(Polrev(base(n,b)),x,b) /* where */
base(n,b)={my(a=[n%b]);while(0M. F. Hasler, Nov 04 2011
a(n) = fromdigits(Vecrev(digits(n, 3)), 3); \\ Michel Marcus, Oct 10 2017
13 in base 9 is 14: moving the least significant digit as the most significant one we have 41 that is 37 in base 10.
with(numtheory): P:=proc(q,h) local a,b,k,n; print(0); for n from 1 to q do a:=convert(n,base,h); b:=[]; for k from 2 to nops(a) do b:=[op(b),a[k]]; od; a:=[op(b),a[1]]; a:=convert(a,base,h,10); b:=0; for k from nops(a) by -1 to 1 do b:=10*b+a[k]; od; print(b); od; end: P(10^4,9);
roll[n_, b_] := Block[{w = IntegerDigits[n, b]}, Prepend[Most@ w, Last@ w]]; b = 9; FromDigits[#, b] & /@ (roll[#, b] & /@ Range[0, 69]) (* Michael De Vlieger, Mar 04 2015 *)
Table[FromDigits[RotateRight[IntegerDigits[n,9]],9],{n,0,80}] (* Harvey P. Dale, Jun 14 2024 *)
f:= proc(n) local L,i; L:= convert(n,base,11); add(L[-i]*11^(i-1),i=1..nops(L)) end proc: map(f, [$0..100]); # Robert Israel, Dec 20 2018
IntegerReverse[Range[0, 100], 11] (* Paolo Xausa, Aug 08 2024 *)
a(n) = fromdigits(Vecrev(digits(n, 11)), 11); \\ Michel Marcus, Dec 20 2018
IntegerReverse[Range[0, 100], 20] (* Paolo Xausa, Aug 08 2024 *)
import Data.List (unfoldr)
a030103 n = foldl (\v d -> 4*v + d) 0 $ unfoldr dig n where
dig x = if x == 0 then Nothing else Just $ swap $ divMod x 4
-- Reinhard Zumkeller, Oct 10 2011
IntegerReverse[Range[0, 100], 4] (* Paolo Xausa, Aug 07 2024 *)
a(n,b=4)=subst(Polrev(base(n,b)),x,b) /* where */
base(n,b)={my(a=[n%b]);while(0M. F. Hasler, Nov 04 2011
(MIT/GNU Scheme)
(define (A030103 n) (if (zero? n) n (let ((uplim (+ (A000523 n) (- 1 (modulo (A000523 n) 2))))) (add (lambda (i) (* (bit_i n (+ i (expt -1 i))) (expt 2 (- uplim i)))) 0 uplim))))
(define (bit_i n i) (modulo (floor->exact (/ n (expt 2 i))) 2))
;; The functional add implements sum_{i=lowlim..uplim} intfun(i):
(define (add intfun lowlim uplim) (let sumloop ((i lowlim) (res 0)) (cond ((> i uplim) res) (else (sumloop (1+ i) (+ res (intfun i)))))))
;; Antti Karttunen, Oct 30 2013
IntegerReverse[Range[0, 100], 5] (* Paolo Xausa, Aug 07 2024 *)
a(n,b=5)=subst(Polrev(base(n,b)),x,b) /* where */
base(n,b)={my(a=[n%b]);while(n\=b,a=concat(n%b,a));a} \\ M. F. Hasler, Nov 04 2011
Table[FromDigits[Reverse[IntegerDigits[n,8]],8],{n,0,80}] (* Harvey P. Dale, Jun 04 2021 *)
a(n,b=8)=subst(Polrev(base(n,b)),x,b) /* where */
base(n,b)={my(a=[n%b]);while(n\=b,a=concat(n%b,a));a} \\ M. F. Hasler, Nov 04 2011
Table[FromDigits[Reverse[IntegerDigits[n,6]],6],{n,0,100}] (* Harvey P. Dale, Nov 18 2021 *)
a(n,b=6)=subst(Polrev(base(n,b)),x,b) /* where */
base(n,b)={my(a=[n%b]);while(0
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