A098382 Partial sums of A098381.

1, 1, 2, 2, 3, 5, 6, 6, 7, 7, 8, 10, 9, 11, 10, 12, 11, 13, 12, 14, 13, 17, 14, 18, 15, 19, 16, 20, 17, 23, 20, 28, 21, 29, 22, 30, 23, 31, 24, 32, 25, 33, 26, 34, 27, 35, 28, 36, 29, 37, 30, 38, 31, 39, 32, 40, 33, 41, 34, 42, 35, 43, 36, 44, 37, 45, 38, 46, 39, 47, 40, 48, 41

Offset

1,3

Comments

a(2n+2)>a(2n) and a(2n+1)>a(2n-1), at least up through the 125th row.

Links

Table of n, a(n) for n=1..73.

Mathematica

a[ 0, 0 ] = 1; a[ m_, n_ ] := a[ m, n ] = Block[ {p = Sort[ Flatten[ Join[ Table[ a[ i, j ], {i, 0, m - 1}, {j, 0, i} ], Table[ a[ i, j ], {i, m, m}, {j, 0, n - 1} ] ] ] ]}, k = Complement[ Range[ p[ [ -1 ] ] + 1 ], p ][ [ 1 ] ]; While[ Position[ p, k ] != {} || If[ n == 0, GCD[ k, a[ m - 1, 0 ] ] != 1, If[ n == m, GCD[ k, a[ m - 1, m - 1 ] ] != 1, GCD[ k, a[ m - 1, n ] ] != 1 || GCD[ k, a[ m - 1, n - 1 ] ] != 1 ] ], k++ ]; k ]; t = Table[ Plus @@ (2Mod[ Table[ a[ m, n ], {n, 0, m} ], 2 ] - 1), {m, 0, 75} ]; Table[ Plus @@ Take[ t, n ], {n, 73} ]

Crossrefs

Cf. A097883, A098381.

Sequence in context: A225489 A308773 A051732 * A098180 A357411 A270875

Adjacent sequences: A098379 A098380 A098381 * A098383 A098384 A098385

Keyword

nonn

Author

Leroy Quet and Robert G. Wilson v, Sep 04 2004

Status

approved