A195840 Triangle read by rows which arises from A195830, in the same way as A175003 arises from A195310. Column k starts at row A074377(k).

1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 3, 1, 4, 1, -1, 4, 1, -1, 4, 1, -1, 4, 1, -1, 4, 2, -1, 5, 3, -1, 7, 4, -1, 10, 4, -2, 12, 4, -3, 13, 4, -4, 13, 4, -4, 13, 5, -4, 14, 7, -4, -1, 16, 10, -4, -1, 21, 12, -5, -1, 27, 13, -7, -1, 32, 13, -10, -1, 34

Offset

1,9

Comments

The sum of terms of row n is equal to the leftmost term of row n+1. This sequence is related to the generalized decagonal numbers A074377, A195830 and A195850 in the same way as A175003 is related to the generalized pentagonal numbers A001318, A195310 and A000041. See comments in A195825.

Links

Table of n, a(n) for n=1..69.

Example

Written as a triangle:
.  1;
.  1;
.  1;
.  1;
.  1;
.  1;
.  1,  1;
.  2,  1;
.  3,  1;
.  4,  1,  -1;
.  4,  1,  -1;
.  4,  1,  -1;
.  4,  1,  -1;
.  4,  2,  -1;
.  5,  3,  -1;
.  7,  4,  -1;
. 10,  4,  -2;
. 12,  4,  -3;
. 13,  4,  -4;
. 13,  4,  -4;
. 13,  5,  -4;
. 14,  7,  -4,  -1;
. 16, 10,  -4,  -1;
. 21, 12,  -5,  -1;
. 27, 13,  -7,  -1;
. 32, 13, -10,  -1;
. 34, 13, -12,  -1,  1;

Crossrefs

Row sums give A195850.

Cf. A001082, A175003, A195828, A195836, A195837, A195838, A195839.

Sequence in context: A195843 A195842 A195841 * A195839 A195838 A195837

Adjacent sequences: A195837 A195838 A195839 * A195841 A195842 A195843

Keyword

sign,tabf

Author

Omar E. Pol, Sep 24 2011

Status

approved