login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A265705 Triangle read by rows: T(n,k) = k IMPL n, 0 <= k <= n, bitwise logical IMPL. 14
0, 1, 1, 3, 2, 3, 3, 3, 3, 3, 7, 6, 5, 4, 7, 7, 7, 5, 5, 7, 7, 7, 6, 7, 6, 7, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 15, 14, 13, 12, 11, 10, 9, 8, 15, 15, 15, 13, 13, 11, 11, 9, 9, 15, 15, 15, 14, 15, 14, 11, 10, 11, 10, 15, 14, 15, 15, 15, 15, 15, 11, 11, 11, 11, 15 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,4
LINKS
Eric Weisstein's World of Mathematics, Implies
FORMULA
T(n,0) = T(n,n) = A003817(n).
T(2*n,n) = A265716(n).
Let m = A089633(n): T(m,k) = T(m,m-k), k = 0..m.
Let m = A158582(n): T(m,k) != T(m,m-k) for at least one k <= n.
Let m = A247648(n): T(2*m,m) = 2*m.
For n > 0: A029578(n+2) = number of odd terms in row n; no even terms in odd-indexed rows.
A265885(n) = T(prime(n),n).
A053644(n) = smallest k such that row k contains n.
EXAMPLE
. 10 | 1010 12 | 1100
. 4 | 100 6 | 110
. ----------+----- ----------+-----
. 4 IMPL 10 | 1011 -> T(10,4)=11 6 IMPL 12 | 1101 -> T(12,6)=13
.
First 16 rows of the triangle, where non-symmetrical rows are marked, see comment concerning A158582 and A089633:
. 0: 0
. 1: 1 1
. 2: 3 2 3
. 3: 3 3 3 3
. 4: 7 6 5 4 7 X
. 5: 7 7 5 5 7 7
. 6: 7 6 7 6 7 6 7
. 7: 7 7 7 7 7 7 7 7
. 8: 15 14 13 12 11 10 9 8 15 X
. 9: 15 15 13 13 11 11 9 9 15 15 X
. 10: 15 14 15 14 11 10 11 10 15 14 15 X
. 11: 15 15 15 15 11 11 11 11 15 15 15 15
. 12: 15 14 13 12 15 14 13 12 15 14 13 12 15 X
. 13: 15 15 13 13 15 15 13 13 15 15 13 13 15 15
. 14: 15 14 15 14 15 14 15 14 15 14 15 14 15 14 15
. 15: 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 .
MAPLE
A265705 := (n, k) -> Bits:-Implies(k, n):
seq(seq(A265705(n, k), k=0..n), n=0..11); # Peter Luschny, Sep 23 2019
MATHEMATICA
T[n_, k_] := If[n == 0, 0, BitOr[2^Length[IntegerDigits[n, 2]]-1-k, n]];
Table[T[n, k], {n, 0, 11}, {k, 0, n}] // Flatten (* Jean-François Alcover, Sep 25 2021, after David A. Corneth's PARI code *)
PROG
(Haskell)
a265705_tabl = map a265705_row [0..]
a265705_row n = map (a265705 n) [0..n]
a265705 n k = k `bimpl` n where
bimpl 0 0 = 0
bimpl p q = 2 * bimpl p' q' + if u <= v then 1 else 0
where (p', u) = divMod p 2; (q', v) = divMod q 2
(PARI) T(n, k) = if(n==0, return(0)); bitor((2<<logint(n, 2))-1-k, n) \\ David A. Corneth, Sep 24 2021
(Julia)
using IntegerSequences
for n in 0:15 println(n == 0 ? [0] : [Bits("IMP", k, n) for k in 0:n]) end # Peter Luschny, Sep 25 2021
CROSSREFS
Cf. A003817, A007088, A029578, A089633, A158582, A247648, A265716 (central terms), A265736 (row sums).
Other triangles: A080099 (AND), A080098 (OR), A051933 (XOR), A102037 (CNIMPL).
Sequence in context: A079790 A098726 A065801 * A205237 A086920 A182021
KEYWORD
nonn,easy,tabl,look
AUTHOR
Reinhard Zumkeller, Dec 15 2015
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 1 06:40 EDT 2024. Contains 372148 sequences. (Running on oeis4.)