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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
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