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A171493 "Kaprekar quadruples": digits of X^4 taken D at a time sum to X (where D is number of digits in X.) 2
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 (list; graph; refs; listen; history; text; internal format)
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
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
Sequence in context: A221541 A327680 A156374 * A262772 A153492 A107125
KEYWORD
base,nonn
AUTHOR
Robert Munafo, Dec 10 2009
EXTENSIONS
Added term a(1)=1, Robert Gerbicz, Jul 28 2011
STATUS
approved

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Last modified May 19 00:35 EDT 2024. Contains 372666 sequences. (Running on oeis4.)