A104613 Write the natural numbers in base 9 in a triangle with k digits in the k-th row, as shown below. Sequence gives the leading diagonal.

1, 3, 6, 0, 1, 1, 0, 4, 3, 3, 1, 7, 5, 6, 1, 0, 1, 1, 1, 1, 1, 3, 1, 1, 6, 1, 1, 0, 2, 2, 3, 2, 2, 7, 2, 3, 2, 3, 3, 6, 3, 4, 2, 4, 4, 7, 5, 5, 3, 5, 5, 0, 6, 6, 6, 6, 7, 3, 7, 7, 1, 8, 8, 8, 1, 3, 0, 0, 8, 1, 6, 6, 1, 0, 2, 2, 7, 1, 4, 6, 1, 0, 4, 4, 7, 1, 0, 4, 1, 1, 6, 6, 0, 1, 3, 0, 1, 4, 8, 0, 3, 2, 4, 3, 2

Offset

1,2

Comments

1

23

456

7810

11121

314151...

Links

Table of n, a(n) for n=1..105.

Mathematica

t = Flatten[ IntegerDigits[ Range[1800], 9]]; t[[Table[n(n + 1)/2, {n, 105}]]]

Prog

(PARI) { pln=0; Trn = 1; Trd=1;
for(ixp=1, 1625, casi = ixp; cvst=0;
while(casi != 0, cvd = casi%9;
cvst=10*cvst + cvd + 1; casi = (casi - cvd) / 9 );
while(cvst !=0, ptch = cvst%10; pln++;
if(Trn==pln, print1(ptch-1, ", "); Trd++; Trn=Trn+Trd);
cvst = (cvst - ptch) / 10 ) ) } \\\ Douglas Latimer, Apr 23 2012

Crossrefs

Cf. A104606, A104607, A104608, A104609, A104610, A104611, A104612, A091425, A104614, A104615, A104616, A104617, A104618, A104619, A104620.

Sequence in context: A071105 A218113 A295194 * A113565 A178567 A182196

Adjacent sequences: A104610 A104611 A104612 * A104614 A104615 A104616

Keyword

base,nonn

Author

Robert G. Wilson v, Mar 16 2005

Status

approved