A067501 Powers of 4 with digit sum also a power of 4.

1, 4, 68719476736, 95780971304118053647396689196894323976171195136475136, 25108406941546723055343157692830665664409421777856138051584, 1606938044258990275541962092341162602522202993782792835301376

Offset: 1

Author

Amarnath Murthy, Feb 11 2002

Keywords

• nonn
• base

Comments

The next term (a(7)) has 915 digits. - Harvey P. Dale, Feb 12 2022

Crossrefs

Cf. A067499, A067500.

Programs

Mathematica

Select[4^Range[0,100],IntegerQ[Log[4,Total[IntegerDigits[#]]]]&] (* Harvey P. Dale, Feb 12 2022 *)

Extensions

More terms from Sascha Kurz, Mar 18 2002

Offset changed by Andrew Howroyd, Sep 17 2024