A218539 - OEIS

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A218539

Numbers that are equal to the sum of the uniform platonic polyhedral (figurate) numbers (tetrahedral, cubic, octahedral, dodecahedral, or icosahedral) on each of their digits.

0, 1, 20, 21, 24, 153, 240, 241, 289, 304, 324, 370, 371, 407, 440, 441, 593, 739, 2167, 2284, 2348, 2484, 2583, 2860, 2861, 3009, 3029, 3093, 3249, 4288, 5859, 6888, 7996, 9898

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OFFSET

1,3

COMMENTS

153, 370, 371, and 407 are well known with regard to the cubic numbers.

LINKS

Table of n, a(n) for n=1..34.

EXAMPLE

The octahedral numbers are represented by the formula, y(x)=(2x^3+x)/3; apply this formula to each of the digits in a(18)=739, i.e., y(7)=231, y(3)=19, y(9)=489; sum=739; the dodecahedral numbers are represented by the formula, y(x)=x(3x-1)(3x-2)/2; apply this formula to each of the digits in a(34)=9898, i.e., y(9)=2725, y(8)=2024; y(9)=2725, y(8)=2024; sum=9898.

CROSSREFS

Cf. A005188, A007532, A036057.

Sequence in context: A241850 A138601 A278582 * A295488 A008940 A014368

Adjacent sequences: A218536 A218537 A218538 * A218540 A218541 A218542

KEYWORD

nonn,base

AUTHOR

Thomas S. Pedigo, Nov 01 2012

STATUS

approved