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A038544 a(n) = Sum_{i=0..10^n} i^3. 4
1, 3025, 25502500, 250500250000, 2500500025000000, 25000500002500000000, 250000500000250000000000, 2500000500000025000000000000, 25000000500000002500000000000000, 250000000500000000250000000000000000, 2500000000500000000025000000000000000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

These terms k = x.y satisfy Diophantine equation x.y = (x+y)^2, when x and y have the same number of digits, "." means concatenation, and y may not begin with 0. So, this is a subsequence of A350870 and A238237. - Bernard Schott, Jan 20 2022

LINKS

Table of n, a(n) for n=0..10.

FORMULA

a(n) = (10^n+1)^2 * 10^(2*n) / 4.

From Bernard Schott, Jan 20 2022: (Start)

a(n) = A037156(n)^2.

a(n) = A350869(n) + 10^(3*n). (End)

EXAMPLE

a(1) = Sum_{i=0..10} i^3 = (Sum_{i=0..10} i)^2 = 3025.

PROG

(PARI) sumcu(n) = for(x=0, n, y=10^x; z=y^2*(y+1)^2/4; (print1(z", "))) - Cino Hilliard, Jun 18 2007

CROSSREFS

Cf. A037156, A238237, A350869, A350870.

Sequence in context: A225996 A167044 A221249 * A252142 A031553 A031733

Adjacent sequences:  A038541 A038542 A038543 * A038545 A038546 A038547

KEYWORD

easy,nonn

AUTHOR

Marvin Ray Burns

EXTENSIONS

Edited by N. J. A. Sloane, Jul 02 2008 at the suggestion of R. J. Mathar

STATUS

approved

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Last modified May 24 07:35 EDT 2022. Contains 354005 sequences. (Running on oeis4.)