A235399 Numbers which are the digital sum of the cube of some prime.

8, 9, 10, 17, 19, 26, 28, 35, 37, 44, 46, 53, 55, 62, 64, 71, 73, 80, 82, 89, 91, 98, 100, 107, 109, 116, 118, 125, 127, 134, 136, 143, 145, 152, 154, 161, 163, 170, 172, 179, 181, 188, 190, 197, 199, 206, 208, 215, 217, 224, 226, 233, 235, 242, 244, 251, 253

Offset

1,1

Comments

A235398 sorted and duplicates removed.

Links

Table of n, a(n) for n=1..57.

Formula

Conjecture: for n > 4, a(n) = a(n-2) + 9 = A056020(n).

Conjecture: a(n) = (1/4)*(-1)^n*(9*(-1)^n*(2*n-1) + 5), n >= 3. - Bill McEachen, Feb 13 2021

Mathematica

Total[IntegerDigits[#]] & /@ (Prime[Range[5000000]]^3) // Union (* The program generates the first 39 terms of the sequence. To generate more, increase the Range constant. *) (* Harvey P. Dale, Sep 19 2021 *)

Prog

(PARI) list(maxx)={v=List(); n=2; while(n<=maxx, q=n^3; summ=sumdigits(q);
if(setsearch(v, summ)<1, listput(v, summ)); n=nextprime(n+1)); vecsort(v, , 8) ; } \\ Bill McEachen, Jan 29 2014

Crossrefs

Cf. A235398, A004164, A007953, A123157.

Sequence in context: A135043 A054966 A130881 * A283628 A343860 A308809

Adjacent sequences: A235396 A235397 A235398 * A235400 A235401 A235402

Keyword

nonn,base

Author

Antonio Graciá Llorente, Jan 09 2014

Extensions

a(37)-a(57) from Lars Blomberg, Feb 10 2016

Status

approved