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A001404 Triangle of values of 2-d recurrence. 1
1, 1, 1, 2, 2, 1, 4, 5, 2, 1, 9, 11, 5, 2, 1, 20, 25, 12, 5, 2, 1, 45, 57, 27, 12, 5, 2, 1, 102, 129, 62, 28, 12, 5, 2, 1, 231, 293, 141, 64, 28, 12, 5, 2, 1, 524, 665, 321, 146, 65, 28, 12, 5, 2, 1, 1189, 1510, 729, 333, 148, 65, 28, 12, 5, 2, 1, 2699, 3428, 1656 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

The first column of the triangle (see example) appears to be A167750. [Joerg Arndt, Jul 09 2012]

LINKS

Table of n, a(n) for n=0..68.

EXAMPLE

Triangle starts

1,

1, 1,

2, 2, 1,

4, 5, 2, 1,

9, 11, 5, 2, 1,

20, 25, 12, 5, 2, 1,

45, 57, 27, 12, 5, 2, 1,

102, 129, 62, 28, 12, 5, 2, 1,

231, 293, 141, 64, 28, 12, 5, 2, 1,

524, 665, 321, 146, 65, 28, 12, 5, 2, 1,

1189, 1510, 729, 333, 148, 65, 28, 12, 5, 2, 1,

MAPLE

a[ 0, 0 ] := 1; for i from 1 to N do a[ i, 0 ] := a[ i-1, 0 ]+a[ i-1, 1 ]; for j from 1 to i do a[ i, j ] := sum(a[ i-j, t ], t=0..min(j+1, N)) od; od;

PROG

(PARI) T(m, n)=if(m<n, 0, if(m==0&&n==0, 1, if(n==0, T(m-1, 0)+T(m-1, 1), sum(t=0, n+1, T(m-n, t))))) /* Ralf Stephan */

CROSSREFS

Cf. A001410.

Sequence in context: A213946 A145036 A272888 * A104580 A202193 A105306

Adjacent sequences:  A001401 A001402 A001403 * A001405 A001406 A001407

KEYWORD

tabl,nonn,easy

AUTHOR

N. J. A. Sloane [ I have temporarily mislaid the name of the person who sent this ]

EXTENSIONS

Sequence corrected by Sean A. Irvine, Jul 08 2012

STATUS

approved

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Last modified January 17 12:33 EST 2020. Contains 330958 sequences. (Running on oeis4.)