A171493 - OEIS

A171493

"Kaprekar quadruples": digits of X^4 taken D at a time sum to X (where D is number of digits in X.)

1, 7, 45, 55, 67, 100, 433, 4950, 5050, 38212, 65068, 190576, 295075, 299035, 310024, 336700, 343333, 394615, 414558, 433566, 448228, 450550, 467236, 475497, 476191, 486486, 499500, 500500, 523513, 534898, 549550, 599743, 622414, 628408, 647362

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OFFSET

1,2

COMMENTS

Referred to as "natural" Kaprekar numbers on Munafo webpage because a(n) and the 4 pieces of a(n)^4 must all have the same number of digits (some of which can be leading zeros). Analogous to A053816 for squares, as opposed to A006886 and A045913 which allow irregular divisions.

LINKS

Robert Gerbicz, Table of n, a(n) for n = 1..10852

R. Munafo, Kaprekar Sequences

EXAMPLE

7^4 = 2401 ; 2+4+0+1 = 7. 67^4 = 20151121 ; 20+15+11+21 = 67. 4950^4 = 600372506250000 ; 0600+3725+0625+0000 = 4950.

CROSSREFS

Cf. A006886, A006887, A045913, A053816

Sequence in context: A221541 A327680 A156374 * A262772 A153492 A107125

Adjacent sequences: A171490 A171491 A171492 * A171494 A171495 A171496

KEYWORD

base,nonn

AUTHOR

Robert Munafo, Dec 10 2009

EXTENSIONS

Added term a(1)=1, Robert Gerbicz, Jul 28 2011

STATUS

approved