A316487 - OEIS

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A316487

Squares whose arithmetic mean of digits is 7 (i.e., the sum of digits is 7 times the number of digits).

2778889, 4695889, 5678689, 5697769, 5938969, 6568969, 6589489, 6848689, 6895876, 7974976, 7997584, 8779369, 9878449, 9966649, 299739969, 377796969, 396686889, 458687889, 467986689, 487658889, 488984769, 496977849, 538889796, 557998884, 559984896, 569967876

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Each term's number of digits is in A056991 (Numbers with digital root 1, 4, 7, or 9). For every term k in A056991, this sequence contains at least one k-digit term, with the exception of k=1 and k=4. (See A316480.)

LINKS

Jon E. Schoenfield, Table of n, a(n) for n = 1..10000

EXAMPLE

17313^2 = 299739969, a 9-digit number whose digit sum is 2+9+9+7+3+9+9+6+9 = 63 = 7*9, so 299739969 is a term.

43474^2 = 1889988676, a 10-digit number whose digit sum is 1+8+8+9+9+8+8+6+7+6 = 70 = 7*10, so 1889988676 is a term.

CROSSREFS

Cf. A056991, A069711, A316480.

Intersection of A000290 and A061424. - Michel Marcus, Jul 06 2018

Sequence in context: A015336 A251835 A295471 * A250535 A203912 A355502

Adjacent sequences: A316484 A316485 A316486 * A316488 A316489 A316490

KEYWORD

nonn,base

AUTHOR

Jon E. Schoenfield, Jul 04 2018

STATUS

approved