A153753 Numbers k such that there are 18 digits in k^2 and for each factor f of 18 (1,2,3,6,9) the sum of digit groupings of size f is a square.

324344373, 333306315, 333321861, 333359685, 333361029, 334363803, 369396732, 370397193, 407380269, 407381484, 444475035, 666636972, 666695028, 666701463, 702667239, 702671124, 702736170, 703667130, 704741610

Offset

1,1

Comments

This sequence is a subsequence of both A153745 and A061910.

Links

Table of n, a(n) for n=1..19.

Example

324344373^2 = 105199272296763129;
1+0+5+1+9+9+2+7+2+2+9+6+7+6+3+1+2+9 = 81 = 9^2;
10+51+99+27+22+96+76+31+29 = 441 = 21^2;
105+199+272+296+763+129 = 1764 = 42^2;
105199+272296+763129 = 1140624 = 1068^2;
105199272+296763129 = 401962401 = 20049^2.

Crossrefs

Cf. A004159, A061910, A153745.

Sequence in context: A112429 A364265 A104923 * A035794 A260083 A344926

Adjacent sequences: A153750 A153751 A153752 * A153754 A153755 A153756

Keyword

nonn,base,fini,full

Author

Doug Bell, Dec 31 2008

Status

approved